The average of 30,42,N,50 is 38. What is the value of N?

"38 x 4 = 152

so when all of them will be added they should arrive at 152

30 + 42 + 50 = 122

152 - 122 = 30

so the N is 30

checking:

30 + 42 + 30 + 50 = 152

152 / 4 = 38"