Mason bought 50% more erasers than Isaac. Ava bought 35% fewer erasers than Mason. Mason and Isaac gave Ava some erasers in the ratio 2 : 1. As a result, Ava had twice as much erasers as before. Given that Mason had 36 less erasers than Isaac in the end, how much erasers did Mason and Isaac give to Ava?

	Mason	Isaac	Ava
	3x20	2x20
	20x3		13x3
Before	60 u	40 u	39 u
Change			+ (2 x 39 u) = + 78 u
	- 2x26 = - 52 u	- 1x26 = - 26 u	+ 3x26 =  + 78 u
After	8 u	14 u	117 u

100% + 50% = 150%
150% = ¹⁵⁰₁₀₀ = ³₂

100% - 35% = 65%
65% = ⁶⁵₁₀₀ = ¹³₂₀

The number of erasers that Mason had at first is the repeated identity.
LCM of 3 and 20 = 60

The change in the number of erasers that Ava had is the repeated identity when Mason and Isaac gave to Ava.
LCM of 78 and 3 = 78

Number of erasers that Mason had less than Isaac in the end
= 14 u - 8 u
= 6 u

6 u = 36
1 u = 36 ÷ 6 = 6

Number of erasers that Mason and Isaac gave to Ava
= 52 u + 26 u
= 78 u
= 78 x 6
= 468

Answer(s): 468