Hilda and Usha collected marbles. Hilda gave 30% of her marbles to Usha and as a result, Usha's marbles increased by 25%. If Hilda had 35 marbles left, find the number of marbles Usha should give to Hilda in the end so that both had an equal number of marbles.

	Hilda	Usha	Comparing the change in Usha's marbles
Before	10x1 = 10 u		4x3 = 12u
Change	- 3x1 = - 3 u	+ 3x1 = + 3 u	+ 1x3 = + 3 u
After	7x1 = 7 u		5x3 = 15 u

30% = ³⁰₁₀₀ = ³₁₀
25% = ²⁵₁₀₀ = ¹₄

The increase in the number of marbles that Usha had is repeated.  Make the increase in the number of marbles that Usha had the same. LCM of 3 and 1 = 3

7 u = 35

1 u = 35 ÷ 7 = 5

Number of marbles that Usha had more than Hilda in the end
= 15 u - 7 u
= 8 u

Number of marbles that Usha should give to Hilda so that both had an equal number of marbles in the end
= 8 u ÷ 2
= 4 u
= 4 x 5
= 20

Answer(s): 20