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

	Shannon	Kathy	Comparing the change in Kathy'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 Kathy had is repeated.  Make the increase in the number of erasers that Kathy had the same. LCM of 1 and 3 = 3

3 u = 30

1 u = 30 ÷ 3 = 10

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

Number of erasers that Kathy should give to Shannon so that both had an equal number of erasers in the end
= 10 u ÷ 2
= 5 u
= 5 x 10
= 50

Answer(s): 50