Question

P, Q, R and S are four consecutive odd numbers and their average is 88. What is the product of Q and R?

Select one:

7890

7860

7743

7677

Answer 1

Correct option is (c) 7743

Let n, n + 2, n + 4, n + 6 are the given consecutive odd numbers is p = n, Q = n + 2, R = n + 4, S = n + 6 then

average = \(\frac{n + n +2 + n + 4 + n + 6}{4} = 88\)  (given)

⇒ \(4n + 12 = 88\times 4\)

⇒ \(4n = 352 - 12 = 340\)

⇒ \(n = \frac{340}4 = 85\)

⇒ \(n = 85\)

\(\therefore \) P = 85, Q = 87, R = 89, S = 91

\(\therefore \) Product of Q and R = 87 x 89 = 7743