Ca

 df <- data.frame(
  BillID = c(501, 502, 503, 504, 505, 506),
  CustomerName = c("Aman", "Riya", "Karan", "Neha", "Rohit", "Simran"),
  Gender = factor(c("Male", "Female", "Male", "Female", "Male", "Female")),
  Membership = factor(c("Gold", "Silver", "Gold", "None", "Silver", "Gold")),
  Category = factor(c("Grocery", "Electronics", "Clothing", "Grocery", "Electronics", "Clothing")),
  Quantity = c(10, 1, 3, 8, 2, 5),
  CostPrice = c(50, 20000, 800, 60, 18000, 700),
  SellingPrice = c(70, 25000, 1000, 80, 22000, 900),
  Discount = c(100, 2000, 150, 50, 500, 300),
  DeliveryType = factor(c("Home", "Store", "Home", "Store", "Home", "Home"))
)

df$grossrevenue = df$Quantity*df$SellingPrice

df

##   BillID CustomerName Gender Membership    Category Quantity CostPrice
## 1    501         Aman   Male       Gold     Grocery       10        50
## 2    502         Riya Female     Silver Electronics        1     20000
## 3    503        Karan   Male       Gold    Clothing        3       800
## 4    504         Neha Female       None     Grocery        8        60
## 5    505        Rohit   Male     Silver Electronics        2     18000
## 6    506       Simran Female       Gold    Clothing        5       700
##   SellingPrice Discount DeliveryType grossrevenue
## 1           70      100         Home          700
## 2        25000     2000        Store        25000
## 3         1000      150         Home         3000
## 4           80       50        Store          640
## 5        22000      500         Home        44000
## 6          900      300         Home         4500

df$totalcost = df$Quantity*df$CostPrice