Charlotte had 50% more stickers than Rachel. Henry had 20% fewer stickers than Charlotte. Charlotte and Rachel gave Henry some stickers in the ratio of 1 : 3. As a result, Henry had 50% more stickers than before. Given that Henry had 250 more stickers than Rachel in the end, how many stickers did Charlotte give to Henry?

Charlotte	Rachel	Henry
3x5	2x5
5x3		4x3
15	10	12

100% + 50% = 150%
150% = ¹⁵⁰₁₀₀ = ³₂

Charlotte : Rachel = 3 : 2

100% - 20% = 80%
80% = ⁸⁰₁₀₀ = ⁴₅

Charlotte : Henry = 5 : 4

The number of stickers that Charlotte had at first is repeated. Make the number of stickers that Charlotte had at first the same.  LCM of 3 and 5 is 15.

	Charlotte	Rachel	Henry
Before	15x2 =  30 u	10x2 = 20 u	12x2 = 24 u
Change			+ 6x2 = + 12 u
Comparing the changes in the number of stickers	- 1x3 = - 3 u	- 3x3 = - 9 u	+ 4x3 = + 12 u
After	27 u	11 u	18x2 = 36 u

50% x 12 
= ⁵⁰₁₀₀ x 12 
= 6 

The total number of stickers that Charlotte and Rachel gave to Henry is repeated.  Make the total number of stickers that Charlotte and Rachel gave to Henry the same.  LCM of 4 and 6 is 12.

Number of stickers that Henry had more than Rachel 
= 36 u - 11 u
= 25 u

25 u = 250

1 u = 250 ÷ 25 = 10

Number of stickers that Charlotte gave to Henry
= 3 u
= 3 x 10
= 30

Answer(s): 30