Irene and Joelle collected stamps. Irene gave 50% of her stamps to Joelle and as a result, Joelle's stamps increased by 30%. If Irene had 33 stamps left, find the number of stamps Joelle should give to Irene in the end so that both had an equal number of stamps.

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

3 u = 33

1 u = 33 ÷ 3 = 11

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

Number of stamps that Joelle should give to Irene so that both had an equal number of stamps in the end
= 10 u ÷ 2
= 5 u
= 5 x 11
= 55

Answer(s): 55