The average of 5 terms is 15. If the first 4 terms are 12, 17, 23 and 8, what will be the fifth term?

30 20 22 15

15

Sum of 5 term = 5 × 15 = 75 Sum of first 4 terms = 12 + 17 + 23 + 8 = 60 5th term = 75 - 60 = 15