Lynn and Linda collected stamps. Lynn gave 25% of her stamps to Linda and as a result, Linda's stamps increased by 30%. If Lynn had 99 stamps left, find the number of stamps Linda should give to Lynn in the end so that both had an equal number of stamps.

	Lynn	Linda	Comparing the change in Linda's stamps
Before	4x3 = 12 u		10x1 = 10u
Change	- 1x3 = - 3 u	+ 1x3 = + 3 u	+ 3x1 = + 3 u
After	3x3 = 9 u		13x1 = 13 u

25% = ²⁵₁₀₀ = ¹₄
30% = ³⁰₁₀₀ = ³₁₀

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

9 u = 99

1 u = 99 ÷ 9 = 11

Number of stamps that Linda had more than Lynn in the end
= 13 u - 9 u
= 4 u

Number of stamps that Linda should give to Lynn so that both had an equal number of stamps in the end
= 4 u ÷ 2
= 2 u
= 2 x 11
= 22

Answer(s): 22