#Order of operations 

(5 * 4) * (4 * 5) - 56
## [1] 344
23 - 1 * (8 - 12)
## [1] 27
56/8 * (3 + 4)
## [1] 49
45-5 * 8 + (8 + 9)
## [1] 22
#Create vector

a<-c(2,5,6,7) 

b<-c(1,0,9,8) 

c<-c(6,5,8,3)
matrix <- rbind(a,b,c)
print(matrix)
##   [,1] [,2] [,3] [,4]
## a    2    5    6    7
## b    1    0    9    8
## c    6    5    8    3
colnames (matrix) <-c ('Mon','Tue','Wed','Thu') 
print(matrix)
##   Mon Tue Wed Thu
## a   2   5   6   7
## b   1   0   9   8
## c   6   5   8   3
rownames(matrix) <-c ('Present','Absent','On leave') 
print(matrix)
##          Mon Tue Wed Thu
## Present    2   5   6   7
## Absent     1   0   9   8
## On leave   6   5   8   3
row_sums <- rowSums(matrix) 
print(row_sums)
##  Present   Absent On leave 
##       20       18       22
col_sums <- colSums(matrix) 
print(col_sums)
## Mon Tue Wed Thu 
##   9  10  23  18