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

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

3 u = 30

1 u = 30 ÷ 3 = 10

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

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

Answer(s): 50