Xavier has 30% as many erasers as Fabian. If Xavier gives away 20% of the erasers and Fabian gives away 10% of his erasers, they will have 228 erasers altogether. How many erasers do the two of them have?

	Xavier	Fabian	Total
Comparing Xavier and Fabian at first	3x5 = 15 u	10x5 = 50 u
Before	5x3 = 15 u	10x5 =  50 u
Change	- 1x3 = - 3 u	- 1x5 = - 5 u
After	4x3 = 12 u	9x5 = 45 u	228

30% = ³⁰₁₀₀ = ³₁₀

20% = ²⁰₁₀₀ = ¹₅ 

10% =¹⁰₁₀₀ = ¹₁₀ 

The number of erasers that Xavier has at first is repeated.  Make the number of erasers that Xavier has the same.  LCM of 3 and 5 is 15 u.

The number of erasers that Fabian has at first is repeated. Make the number of erasers that Fabian has the same. LCM of 10 and 10 is 50 u.

Number of erasers in the end
= 12 u + 45 u
= 57 u

57 u = 228

1 u = 228 ÷ 57 = 4

Total number of erasers that the two of them have
= 15 u + 50 u
= 65 u
= 65 x 4
= 260

Answer(s): 260