# What number is needed to complete the pattern below? 66 73 13 21 52 __ 10 20

**Solution:**

Given, the pattern is 66 73 12 21 52 _____ 10 20

First, understand the pattern

By subtracting the second number from the first number and fourth number from the third number and so on, we get

73 - 66 = 7

21 - 13 = 8

52 - xx = y

20 - 10 = 10

Based on the pattern, y should be 9.

So, 52 - xx = 9

xx = 52 - 9

xx = 61

Therefore, the missing number is 61.

## What number is needed to complete the pattern below? 66 73 13 21 52 __ 10 20

**Summary:**

The number needed to complete the pattern 66 73 13 21 52 __ 10 20 is 61.