Question

5,25,15,75,45,? find

Answer 1

Solution :-

5, 25, 15, 75, 45 ?

If we see this number series closely, we will find that there is a definite pattern in it.

5, 15, 45

⇒ 5 × 3 = 15 ; 15 × 3 = 45 ; 45 × 3 = 135 ; 135 × 3 = 405

25, 75

⇒ 25 × 3 = 75 ; 75 × 3 = 225 ; 225 × 3 = 675

So, next four numbers in this series will be 225, 135, 675, 405

The series will be like this -

5, 25, 15, 75, 45, 225, 135, 675, 405....

Answer.

Answer 2

Here given, 5 , 25 , 15 , 75 ,?
It seems , given series is combination of two different series.
if we write $\it{5},\bf{25},\it{15},\bf{75},....$
Here seperate the numbers which are written by italic font.
And also separate the numbers which are written by bold font.

e.g., first series is 5 , 15 , ....
It relates 5 × 3 = 15
15 × 3 = 45
45 × 3 = 135 and so on

2nd series is 25 , 75 ....
it relates 25 × 3 = 75
75 × 3 = 225
225 × 3 = 675 and so on

Hence, now our series is 5 , 25 , 15 , 75 ,$\bf{45}$
So, next number is 45