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

	Pamela	Anna	Comparing the change in Anna's erasers
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 erasers that Anna had is repeated.  Make the increase in the number of erasers that Anna had the same. LCM of 3 and 1 = 3

2 u = 20

1 u = 20 ÷ 2 = 10

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

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

Answer(s): 80