# In the Following Series of Numbers, Find Out the Missing Number:

50, 65, (..), 101, 122.

- 73
- 82
- 89
- 93

**Correct answer should be = 82**

Explanation: In given series 50, 65, … , 101, 122 there is a difference between two adjacent numbers. And this difference also forms a Arithmetic Progression series.

Let us consider desired number is ‘x’.

Difference between two adjacent number of this series is given below:

65 – 50 = 15

x – 65 = ?

101 – x = ?

122 – 101 = 21

There is a difference of 6 (21-15). So by taking two numbers between 15 and 21 we get = 17 and 19

Let us put it in the series we,

50, 65, 82, 101, 121

Difference between number of series will be 15, 17, 19 and 21.