Yen and Esther collected erasers. Yen gave 50% of her erasers to Esther and as a result, Esther's erasers increased by 30%. If Yen had 27 erasers left, find the number of erasers Esther should give to Yen in the end so that both had an equal number of erasers.

	Yen	Esther	Comparing the change in Esther's erasers
Before	2x3 = 6 u		10x1 = 10u
Change	- 1x3 = - 3 u	+ 1x3 = + 3 u	+ 3x1 = + 3 u
After	1x3 = 3 u		13x1 = 13 u

50% = ⁵⁰₁₀₀ = ¹₂
30% = ³⁰₁₀₀ = ³₁₀

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

3 u = 27

1 u = 27 ÷ 3 = 9

Number of erasers that Esther had more than Yen in the end
= 13 u - 3 u
= 10 u

Number of erasers that Esther should give to Yen so that both had an equal number of erasers in the end
= 10 u ÷ 2
= 5 u
= 5 x 9
= 45

Answer(s): 45