Rachel and Hilda collected erasers. Rachel gave 25% of her erasers to Hilda and as a result, Hilda's erasers increased by 30%. If Rachel had 108 erasers left, find the number of erasers Hilda should give to Rachel in the end so that both had an equal number of erasers.

	Rachel	Hilda	Comparing the change in Hilda's erasers
Before	4x3 = 12 u		10x1 = 10u
Change	- 1x3 = - 3 u	+ 1x3 = + 3 u	+ 3x1 = + 3 u
After	3x3 = 9 u		13x1 = 13 u

25% = ²⁵₁₀₀ = ¹₄
30% = ³⁰₁₀₀ = ³₁₀

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

9 u = 108

1 u = 108 ÷ 9 = 12

Number of erasers that Hilda had more than Rachel in the end
= 13 u - 9 u
= 4 u

Number of erasers that Hilda should give to Rachel so that both had an equal number of erasers in the end
= 4 u ÷ 2
= 2 u
= 2 x 12
= 24

Answer(s): 24