Gabby and Nicole collected cards. Gabby gave 50% of her cards to Nicole and as a result, Nicole's cards increased by 30%. If Gabby had 15 cards left, find the number of cards Nicole should give to Gabby in the end so that both had an equal number of cards.

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

3 u = 15

1 u = 15 ÷ 3 = 5

Number of cards that Nicole had more than Gabby in the end
= 13 u - 3 u
= 10 u

Number of cards that Nicole should give to Gabby so that both had an equal number of cards in the end
= 10 u ÷ 2
= 5 u
= 5 x 5
= 25

Answer(s): 25