The average of 10 numbers is 42. If each number is increased by 5, them what will be the new average?

47

Average of 10 numbers = $\frac{sum of the numbers}{10}$ 

                                  = 42(given)

Thus, sum of the numbers = 42 x 10 = 420

Now, each number is increased by 5, then total sum is increased by 5 x 10 = 50

New sum of the numbers = 420 + 50 = 470

New average = $\frac{470}{10}$ = 47