#create this matrix mymat<-matrix(1:20,nrow=5,byrow=T) # # it should look like this # [,1] [,2] [,3] [,4] #[1,] 1 2 3 4 #[2,] 5 6 7 8 #[3,] 9 10 11 12 #[4,] 13 14 15 16 #[5,] 17 18 19 20 # compute the column sums 3 different ways: #a) with 2 nested loops but without any functions like sum() or apply() #b) using one loop and you are allowed to use a function such as sum() #c) you are not allowed to use any loops but you will likely need to use apply()solution