Explanation

To convert 2/5 to a percentage:

First, convert the fraction to a decimal:

2/5 = 2 ÷ 5 = 0.4

Now, convert the decimal to a percentage:

0.4 × 100% = 40%

Explanation

To find the ratio between their ages, we need to convert their ages to a common unit (months):
Ashraf's age:
15 years × 12 months/year = 180 months

- 10 months = 190 months

Akmal's age:
17 years × 12 months/year = 204 months

- 5 months = 209 months

Now, find the ratio:
Ashraf's age : Akmal's age = 190 : 209
Simplify the ratio:
190 ÷ 19 = 10
209 ÷ 19 = 11
So, the ratio is:
10 : 11

Explanation

The mean proportional of two numbers is the square root of their product.

Mean proportional = √(4 × 16) = √64 = 8

Explanation

25% of 200 is calculated by

multiplying 200 by 25/100,

which equals 50.

Explanation

The given series is a square of natural number

(1)^2 = 1

(2)^2 = 4

(3)^2 =9

(4)^2 = 16

(5)^2 = 25