Xandra and Rachel collected stamps. Xandra gave 30% of her stamps to Rachel and as a result, Rachel's stamps increased by 10%. If Xandra had 63 stamps left, find the number of stamps Rachel should give to Xandra in the end so that both had an equal number of stamps.

	Xandra	Rachel	Comparing the change in Rachel's stamps
Before	10x1 = 10 u		10x3 = 30u
Change	- 3x1 = - 3 u	+ 3x1 = + 3 u	+ 1x3 = + 3 u
After	7x1 = 7 u		11x3 = 33 u

30% = ³⁰₁₀₀ = ³₁₀
10% = ¹⁰₁₀₀ = ¹₁₀

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

7 u = 63

1 u = 63 ÷ 7 = 9

Number of stamps that Rachel had more than Xandra in the end
= 33 u - 7 u
= 26 u

Number of stamps that Rachel should give to Xandra so that both had an equal number of stamps in the end
= 26 u ÷ 2
= 13 u
= 13 x 9
= 117

Answer(s): 117