Question

please explain me the solution of this question.

Answer 1

Given Series : 7 , 23 , ? , 79 , 119

We can notice that :

★  Difference between 23 and 7 is : (23 - 7) = 16

★  Difference between 119 and 79 is : (119 - 79) = 40

As, It is a short series and the difference between the first two numbers and last two numbers are 16 and 40 respectively, We can conclude that the difference between each pair of numbers starting from the first two numbers is a multiple of 8 (starting from 16)

That is :

★  Difference between first pair of numbers is 16

★  Difference between second pair of numbers is 24

★  Difference between third pair of numbers is 32

★  Difference between fourth pair of numbers is 40

It means :

★  23 - 7 = 16

★  ? - 23 = 24   ----------------- [1]

★  79 - ? = 32   ----------------- [2]

★  119 - 79 = 40

Consider Equation [1] :

$:\implies$  ? - 23 = 24

$:\implies$  ? = 24 + 23

$:\implies$  ? = 47

Consider Equation [2] :

$:\implies$  79 - ? = 32

$:\implies$  ? = 79 - 32

$:\implies$  ? = 47

Answer  $:\implies$  ? = 47