Yoko and Marion collected cards. Yoko gave 30% of her cards to Marion and as a result, Marion's cards increased by 10%. If Yoko had 28 cards left, find the number of cards Marion should give to Yoko in the end so that both had an equal number of cards.

	Yoko	Marion	Comparing the change in Marion's cards
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 cards that Marion had is repeated.  Make the increase in the number of cards that Marion had the same. LCM of 3 and 1 = 3

7 u = 28

1 u = 28 ÷ 7 = 4

Number of cards that Marion had more than Yoko in the end
= 33 u - 7 u
= 26 u

Number of cards that Marion should give to Yoko so that both had an equal number of cards in the end
= 26 u ÷ 2
= 13 u
= 13 x 4
= 52

Answer(s): 52