Question

Find the missing Number 3,5,18,72,?

Answer 1

First of all, I think that the no. '5' should be '6' as per as the series.

So the missing no. or the '?' is 360.

As - The pattern is  × 2, × 3, × 4,...
 
∴Missing number = 72 × 5 = 360.

Hope this helps,
@PoojaBBSR

Answer 2

Answer:

320

Step-by-step explanation:

The given number series is

3,5,18,72,?

We need to find the missing number in the given series.

$3\times 1+2\times 1^2=5$

$5\times 2+2\times 2^2=18$

$18\times 3+2\times 3^2=72$

The nth term is defined by the formula:

$a_n=a_{n-1}\times (n-1)+2\times (n-1)^2$

The fifth term of the series is

$a_5=a_{5-1}\times (5-1)+2\times (5-1)^2$

$a_5=a_{4}\times (4)+2\times (4)^2$

 $a_5=72\times 4+2\times 4^2=320$

Therefore the missing number is 320.