A number is 2/5 times of another number. If the sum of two numbers is 98, what is the difference of the two numbers?

Question: A number is 2/5 times of another number. If the sum of two numbers is 98, what is the difference of the two numbers?

Solution:
Let, a number is x
another number is 2x/5

ATQ,
x + 2x/5 = 98
⇒ (5x + 2x)/5 = 98
⇒ 7x/5 = 98
⇒ 7x = 98 × 5
⇒ 7x = 490
∴ x = 70

So, a number is 70
another number is 2x/5 = (2 × 70)/5 = 28
∴ Difference = 70 - 28
= 42