Anna and Shannon collected cards. Anna gave 60% of her cards to Shannon and as a result, Shannon's cards increased by 20%. If Anna had 20 cards left, find the number of cards Shannon should give to Anna in the end so that both had an equal number of cards.

	Anna	Shannon	Comparing the change in Shannon's cards
Before	5x1 = 5 u		5x3 = 15u
Change	- 3x1 = - 3 u	+ 3x1 = + 3 u	+ 1x3 = + 3 u
After	2x1 = 2 u		6x3 = 18 u

60% = ⁶⁰₁₀₀ = ³₅
20% = ²⁰₁₀₀ = ¹₅

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

2 u = 20

1 u = 20 ÷ 2 = 10

Number of cards that Shannon had more than Anna in the end
= 18 u - 2 u
= 16 u

Number of cards that Shannon should give to Anna so that both had an equal number of cards in the end
= 16 u ÷ 2
= 8 u
= 8 x 10
= 80

Answer(s): 80