Answer : As per the question, a, b and c are the pth, qth and rth term of GP. Let us assume the required GP as A, AR, AR2, AR3…
Now, the nth term in the GP, an = ARn-1 pth term, ap = ARp-1 = a → (1)
qth term, aq = ARq-1 = b → (2) rth term, ar = ARr-1 = c → (3)