### IBPS RRB PO 2018 Question 4

Instructions

In each of these questions, a number series is given. Only one number is wrong in each series. You have to find out the wrong number

Question 4

# 2, 8, 32, 148, 765, 4626, 32431

Solution

$$32431 = 7 \times 4626 + 7^2$$
$$4626 = 6 \times 765 + 6^2$$
$$765 = 5 \times 148 + 5^2$$
Following the same pattern,
$$148 = 4 \times 33 + 4^2$$
$$33 = 3 \times 8 + 3^2$$
$$8 = 2 \times 2 + 2^2$$

32 is the wrong number here.