1

\(P(red \ OR \ blue) = P(red) + P(blue)\)

Total Marbles = 138

\(P(red) = \frac{54}{138} = \frac{9}{23}\) = .03913

\(P(blue) = \frac{75}{138}\) = 0.5435

\(P(red)+P(blue)\) = 0.9348

2

\(P(red) = \frac{P(red)}{P(total)} = \frac{20}{80} =\) 0.25

3

\(P(not \ male \cup not \ in \ parent's \ house)= 1 - P(male \cap in \ parent's \ house)\)

\(P(male) = \frac{671}{1399} = 0.4796\)

\(P(in \ parent's \ house) = \frac{467}{1399} = 0.3338\)

\(0.4796 \times 0.3338 = 0.16\)

\(1 - 0.16 =\) 0.84

4

Dependent

5

\[\left (\begin{array}{c} 8 \\ 3 \end{array} \right) \times \left (\begin{array}{c} 7 \\ 3 \end{array} \right) \times 3 \]
\[\left (\begin{array}{c} 8 \\ 3 \end{array} \right) = \frac{8!}{3!(8-3)!} = 56 \] \[\left (\begin{array}{c} 7 \\ 3 \end{array} \right) = \frac{7!}{3!(7-3)!} = 35 \] \(56 \times 35 \times 3 =\) 5880

56*35*3
## [1] 5880

6

Independent

7

\[\frac{14!}{(14-8)!} = 121080960\]

8

Total number of ways 4 jelly beans can be drawn from 22. \[\left (\begin{array}{c} 22 \\ 4 \end{array} \right)\]

Number of ways to pick 1 orange jelly beans \[\left (\begin{array}{c} 4 \\ 1 \end{array} \right)\]

Number of ways to pick 3 green jelly beans \[\left (\begin{array}{c} 9 \\ 3 \end{array} \right)\]

Probability of choosing 3 green and 1 orange jelly beans \[\frac{\left (\begin{array}{c} 4 \\ 1 \end{array} \right) \left (\begin{array}{c} 9 \\ 3 \end{array} \right)}{\left (\begin{array}{c} 22 \\ 4 \end{array} \right)} = 0.0459 \]

9

factorial(11)/factorial(7)
## [1] 7920

10

33% of subscribers to a fitness magazine are under the age of 34

11

Step 1)

Total outcomes = \(2^4 = 16\)

Number of ways to get 3 heads = \[\left (\begin{array}{c} 4 \\ 3 \end{array} \right) = 4\]

P(3 heads) = \(\frac{4}{16} = \frac{1}{4} = (+\$97)\) P(not 3 heads) = \(\frac{3}{4} = (-\$30)\)

\((0.25 \times 97) + (.75 \times -30) = \$1.75\)

Step 2)

\(\$1.75 \times 559 = \$978.25\)

outcome <- c()
coin <- c(0,1) #tails = 0, heads = 1
prob <- 0.5 #fair coin
n <- 559 #number of times to flip
i <- 1

while(i <= n){
 set <- sample(coin, size = 4, replace = TRUE, prob = c(.5,.5))
 if(sum(set) == 3) {outcome <- c(outcome, sum(outcome[i-1], 97))}
 else {outcome <- c(outcome, sum(outcome[i-1], -30))}   
 i <- i + 1
}
outcome
##   [1]  -30  -60   37    7  -23   74   44   14  111   81  178  148  118   88
##  [15]   58  155  125   95  192  162  132  102  199  169  139  236  206  176
##  [29]  146  116   86  183  153  123   93   63   33    3  -27  -57  -87 -117
##  [43] -147 -177 -207 -110  -13  -43  -73   24   -6  -36  -66  -96 -126 -156
##  [57]  -59  -89 -119 -149 -179 -209 -112 -142 -172  -75 -105 -135  -38   59
##  [71]   29   -1  -31  -61  -91 -121  -24  -54   43   13  -17   80   50  147
##  [85]  117   87   57   27  124   94   64   34  131  101   71   41   11  -19
##  [99]  -49  -79 -109 -139  -42   55  152  122   92   62   32    2  -28  -58
## [113]   39  136  106   76   46  143  113   83   53   23   -7   90   60   30
## [127]  127   97   67   37    7  -23  -53  -83   14  -16  -46  -76 -106   -9
## [141]  -39  -69  -99 -129  -32  -62  -92 -122  -25  -55  -85   12  -18  -48
## [155]  -78 -108 -138 -168 -198 -228 -258 -288 -318 -221 -251 -154 -184 -214
## [169] -244 -274 -304 -207 -237 -267 -297 -200 -230 -260 -290 -320 -350 -253
## [183] -156  -59  -89 -119 -149 -179  -82 -112 -142 -172 -202 -232 -135  -38
## [197]   59   29  126  223  320  417  514  484  454  424  394  491  461  558
## [211]  528  498  468  438  408  505  475  445  415  385  355  325  295  265
## [225]  362  332  302  272  369  339  309  406  376  346  316  286  256  226
## [239]  196  166  263  233  203  173  270  367  464  434  404  374  471  568
## [253]  538  508  478  448  418  388  358  328  425  522  619  589  559  656
## [267]  753  850  947 1044 1014 1111 1081 1051 1021  991  961  931  901  871
## [281]  841  811  781  751  721  691  661  758  728  698  668  638  608  578
## [295]  675  645  742  712  809  779  749  719  689  659  629  599  696  793
## [309]  763  860  957 1054 1024  994 1091 1061 1031 1001  971  941  911 1008
## [323] 1105 1202 1172 1142 1239 1209 1179 1149 1119 1089 1059 1029  999 1096
## [337] 1066 1163 1133 1230 1327 1297 1267 1237 1207 1304 1274 1244 1214 1184
## [351] 1154 1124 1094 1064 1034 1004 1101 1071 1168 1138 1108 1078 1048 1018
## [365] 1115 1085 1055 1025  995  965  935  905  875  845  815  912  882  852
## [379]  949 1046 1143 1240 1210 1180 1150 1120 1090 1060 1030 1000  970  940
## [393] 1037 1007 1104 1074 1044 1014  984  954  924 1021  991  961  931 1028
## [407] 1125 1222 1192 1162 1132 1102 1072 1169 1139 1236 1206 1303 1400 1497
## [421] 1594 1564 1534 1504 1474 1444 1414 1384 1354 1324 1294 1264 1234 1331
## [435] 1301 1271 1241 1211 1181 1151 1121 1091 1061 1158 1128 1225 1195 1165
## [449] 1262 1359 1329 1299 1396 1493 1463 1433 1403 1500 1597 1694 1791 1888
## [463] 1985 1955 1925 1895 1865 1835 1805 1775 1745 1715 1685 1655 1625 1722
## [477] 1819 1789 1886 1856 1826 1796 1766 1736 1706 1676 1646 1616 1586 1556
## [491] 1526 1623 1593 1690 1660 1630 1727 1697 1667 1637 1607 1704 1674 1644
## [505] 1741 1711 1681 1651 1621 1591 1561 1531 1501 1471 1568 1665 1635 1605
## [519] 1702 1672 1769 1739 1709 1806 1903 1873 1970 1940 1910 2007 2104 2074
## [533] 2044 2014 1984 1954 1924 1894 1991 1961 2058 2028 1998 1968 1938 1908
## [547] 1878 1848 1818 1788 1885 1982 1952 2049 2146 2116 2086 2183 2153

12

Step 1)

Total outcomes = \(2^9 = 512\)

Number of ways to get 4 tails or less = \[\left (\begin{array}{c} 9 \\ 4 \end{array} \right) + \left (\begin{array}{c} 9 \\ 3 \end{array} \right) + \left (\begin{array}{c} 9 \\ 2 \end{array} \right) + \left (\begin{array}{c} 9 \\ 1 \end{array} \right) + 1 = 256 \]

P(4 tails or less) = \(\frac{256}{512} = \frac{1}{2} = (+\$23)\) P(not 4 tails or less) = \(\frac{1}{2} = (-\$26)\)

\((0.5 \times 23) + (.5 \times -26) = \$1.50\)

Step 2)

\(\$1.75 \times 994 = \$-1,491\)

outcome <- c()
coin <- c(0,1) #tails = 0, heads = 1
prob <- 0.5 #fair coin
n <- 994 #number of times to flip
i <- 1

while(i <= n){
 set <- sample(coin, size = 9, replace = TRUE, prob = c(.5,.5))
 if(sum(set) >= 5) {outcome <- c(outcome, sum(outcome[i-1], 23))}
 else {outcome <- c(outcome, sum(outcome[i-1], -26))}   
 i <- i + 1
}
outcome
##   [1]    23    -3   -29   -55   -81   -58   -35   -12   -38   -15     8
##  [12]    31     5   -21     2   -24   -50   -76   -53   -79  -105   -82
##  [23]   -59   -85  -111   -88  -114  -140  -117  -143  -120   -97   -74
##  [34]   -51   -77  -103   -80   -57   -83   -60   -37   -63   -40   -17
##  [45]     6    29    52    75    49    72    46    69    43    17    -9
##  [56]   -35   -61   -38   -15   -41   -18   -44   -21     2   -24    -1
##  [67]   -27   -53   -30   -56   -82  -108  -134  -111   -88  -114   -91
##  [78]  -117  -143  -169  -146  -123  -100  -126  -103   -80  -106   -83
##  [89]  -109   -86   -63   -89   -66   -43   -20   -46   -72   -98  -124
## [100]  -101  -127  -153  -130  -107   -84   -61   -38   -15     8   -18
## [111]   -44   -70   -96  -122   -99   -76  -102   -79  -105   -82  -108
## [122]  -134  -160  -137  -114   -91  -117  -143  -169  -146  -123  -149
## [133]  -126  -103   -80   -57   -34   -11   -37   -14     9   -17   -43
## [144]   -20   -46   -23   -49   -26    -3   -29    -6   -32    -9    14
## [155]   -12    11    34    57    31     5   -21     2   -24   -50   -27
## [166]    -4   -30   -56   -33   -10   -36   -62   -88  -114  -140  -166
## [177]  -192  -218  -244  -270  -296  -273  -299  -325  -351  -377  -403
## [188]  -380  -406  -383  -409  -386  -412  -389  -366  -343  -369  -346
## [199]  -372  -349  -375  -352  -329  -355  -381  -407  -384  -410  -387
## [210]  -364  -390  -367  -393  -419  -396  -422  -399  -376  -402  -428
## [221]  -454  -431  -408  -385  -362  -339  -365  -342  -319  -345  -322
## [232]  -348  -374  -400  -426  -452  -429  -455  -481  -458  -484  -461
## [243]  -438  -415  -441  -418  -395  -421  -398  -424  -401  -378  -355
## [254]  -381  -407  -433  -459  -485  -511  -488  -514  -540  -517  -543
## [265]  -569  -595  -572  -598  -624  -650  -676  -653  -630  -607  -633
## [276]  -659  -636  -613  -639  -665  -642  -619  -596  -622  -648  -625
## [287]  -602  -579  -556  -533  -510  -487  -464  -441  -418  -395  -372
## [298]  -349  -375  -401  -378  -404  -430  -407  -433  -410  -436  -413
## [309]  -390  -416  -442  -419  -445  -422  -448  -425  -451  -428  -454
## [320]  -480  -506  -483  -509  -535  -561  -538  -564  -590  -616  -642
## [331]  -619  -596  -573  -550  -576  -553  -530  -556  -533  -559  -536
## [342]  -513  -539  -516  -493  -470  -447  -424  -450  -427  -404  -430
## [353]  -407  -433  -459  -485  -511  -488  -465  -491  -517  -494  -471
## [364]  -497  -523  -549  -575  -552  -578  -555  -532  -509  -535  -512
## [375]  -538  -564  -590  -616  -593  -619  -596  -573  -550  -576  -602
## [386]  -579  -556  -582  -608  -634  -660  -637  -663  -689  -666  -692
## [397]  -669  -646  -672  -649  -626  -652  -678  -655  -632  -609  -586
## [408]  -612  -638  -615  -592  -569  -595  -572  -549  -526  -552  -578
## [419]  -555  -532  -509  -486  -463  -440  -417  -443  -420  -397  -423
## [430]  -400  -377  -354  -380  -357  -334  -311  -337  -363  -389  -366
## [441]  -343  -320  -346  -372  -349  -375  -401  -378  -404  -430  -456
## [452]  -433  -410  -436  -413  -439  -465  -491  -517  -543  -569  -546
## [463]  -572  -549  -526  -552  -529  -506  -532  -509  -486  -512  -489
## [474]  -466  -443  -420  -446  -472  -449  -426  -452  -478  -455  -481
## [485]  -507  -533  -559  -536  -562  -588  -565  -542  -568  -545  -571
## [496]  -597  -623  -600  -626  -603  -629  -655  -632  -658  -684  -710
## [507]  -687  -664  -641  -618  -644  -621  -598  -624  -650  -627  -653
## [518]  -679  -705  -682  -708  -685  -662  -639  -665  -691  -717  -694
## [529]  -720  -697  -674  -700  -726  -703  -729  -755  -732  -758  -784
## [540]  -810  -836  -862  -888  -865  -842  -868  -845  -822  -799  -776
## [551]  -753  -730  -756  -733  -710  -736  -713  -739  -765  -791  -768
## [562]  -794  -820  -846  -872  -898  -875  -852  -829  -855  -881  -907
## [573]  -884  -910  -936  -913  -890  -916  -893  -919  -945  -971  -948
## [584]  -974  -951  -977  -954  -931  -957  -934  -911  -888  -865  -842
## [595]  -868  -845  -822  -848  -874  -900  -926  -903  -929  -955  -932
## [606]  -909  -935  -961  -938  -964  -990  -967  -993 -1019  -996 -1022
## [617] -1048 -1074 -1100 -1126 -1152 -1129 -1155 -1181 -1207 -1184 -1210
## [628] -1187 -1164 -1141 -1167 -1144 -1121 -1147 -1173 -1150 -1127 -1153
## [639] -1130 -1156 -1182 -1159 -1185 -1211 -1188 -1165 -1142 -1119 -1096
## [650] -1073 -1050 -1076 -1102 -1128 -1154 -1180 -1157 -1134 -1111 -1137
## [661] -1114 -1140 -1166 -1143 -1169 -1195 -1172 -1198 -1224 -1250 -1276
## [672] -1302 -1328 -1305 -1282 -1308 -1334 -1311 -1288 -1314 -1291 -1268
## [683] -1245 -1222 -1199 -1225 -1202 -1228 -1205 -1182 -1159 -1136 -1113
## [694] -1139 -1165 -1191 -1217 -1194 -1220 -1197 -1174 -1151 -1177 -1203
## [705] -1180 -1157 -1183 -1209 -1235 -1261 -1287 -1264 -1290 -1267 -1293
## [716] -1270 -1247 -1224 -1201 -1178 -1155 -1132 -1109 -1086 -1112 -1138
## [727] -1164 -1190 -1216 -1242 -1268 -1294 -1320 -1297 -1274 -1300 -1326
## [738] -1303 -1329 -1306 -1283 -1260 -1286 -1263 -1289 -1266 -1292 -1269
## [749] -1246 -1272 -1249 -1226 -1252 -1229 -1206 -1183 -1160 -1186 -1163
## [760] -1189 -1166 -1143 -1120 -1097 -1123 -1149 -1175 -1152 -1129 -1106
## [771] -1083 -1109 -1135 -1161 -1187 -1213 -1239 -1216 -1242 -1219 -1245
## [782] -1271 -1297 -1274 -1300 -1277 -1254 -1280 -1306 -1332 -1358 -1335
## [793] -1312 -1289 -1315 -1292 -1318 -1295 -1321 -1298 -1275 -1301 -1327
## [804] -1353 -1330 -1356 -1382 -1359 -1385 -1362 -1339 -1316 -1342 -1319
## [815] -1296 -1322 -1348 -1325 -1302 -1279 -1256 -1282 -1308 -1285 -1262
## [826] -1288 -1265 -1242 -1268 -1245 -1222 -1199 -1176 -1153 -1130 -1156
## [837] -1133 -1110 -1136 -1113 -1139 -1165 -1142 -1168 -1145 -1122 -1099
## [848] -1076 -1053 -1030 -1007 -1033 -1059 -1085 -1111 -1137 -1114 -1091
## [859] -1068 -1094 -1071 -1048 -1074 -1051 -1028 -1054 -1031 -1008  -985
## [870]  -962  -988 -1014 -1040 -1066 -1092 -1118 -1144 -1121 -1098 -1075
## [881] -1101 -1078 -1055 -1081 -1107 -1084 -1110 -1136 -1113 -1090 -1116
## [892] -1142 -1119 -1096 -1073 -1050 -1076 -1102 -1128 -1105 -1131 -1157
## [903] -1183 -1160 -1186 -1212 -1189 -1166 -1143 -1169 -1146 -1123 -1100
## [914] -1126 -1103 -1129 -1106 -1083 -1060 -1037 -1014  -991  -968  -945
## [925]  -922  -948  -974 -1000 -1026 -1003  -980  -957  -983 -1009  -986
## [936] -1012  -989  -966  -992  -969  -995  -972  -998 -1024 -1050 -1027
## [947] -1053 -1030 -1007  -984  -961  -938  -915  -941  -967  -944  -970
## [958]  -996  -973  -999  -976  -953  -979  -956  -933  -910  -936  -962
## [969]  -939  -916  -942  -919  -896  -922  -948  -974 -1000  -977  -954
## [980]  -931  -908  -934  -911  -937  -963  -940  -917  -894  -920  -946
## [991]  -923  -949  -926  -903

13

Detecting Liar: \(P(DL) = 0.59\)

Detecting Truth: \(P(DT) = 0.9\)

Probability of Someone Lying: \(P(L) = 0.2\)

  1. Total probability of detecting a liar: \(P(DL)\times P(L) + P(1-DT)\times P(1-L) = (.59*.2)+(.1*.8) = 0.198\)

Prob of being a liar after being detected: \(P(DL) \times P(L) = 0.59*0.2 = .118\)

So, \(\frac{.118}{.198} = 0.6\)

  1. Total probability of detecting a truth-teller: \(P(DT)\times P(1-L) + P(1-DL)\times P(L) = (.9*.8)+(.41*.2) = 0.802\)

Prob of being a truth-teller after being detected: \(P(DT)\times P(1-L) = .9*.8 = .72\)

So, \(\frac{.72}{.802} = 0.9\)

  1. Probability of being a liar: \(P(L) = 0.2\)

Prob of being identified as a liar:

  1. Prob of NOT detecting the truth in a random person: \(P(1-L)\times P(1-DT) = .1 * .8 = 0.08\)

  2. Total probability of detecting a liar in a radom person: \(P(DL)\times P(L) + P(1-L)\times P(1-DT) = .59*.2+.1*.8 = 0.198\)

So, \(\frac{.08}{.198} = .4\)

Probability of being a liar or being identified as a liar: \(.4 + .198 = 0.6\)