Question

Determine the AP whose third term is 16 and the 7th term exceeds the 5th term by 12.

Answer 1

Solution: As the 7th term exceeds the 5th term by 12, so the 5th term will exceed the 3rd term by 12 as well
So, n₃ = 16
n₅ = 28
n₇ = 40
n₄ or n₆ can be calculated by taking an average of the preceding and next term
So, n₄ = (28+16)/2 = 22

This gives the d = 6
AP: 4, 10, 16, 22, 28, 34, 40, 46, ……..