Oscar, Andy and Corwin collected erasers in the ratio of 11 : 8 : 9. After Corwin gave ³₅ to Oscar and Andy, Corwin had 288 less erasers than Oscar. The number of erasers that Andy had increased by 40%. How many erasers did Oscar and Corwin have in the end?

	Oscar	Andy	Corwin
Before	11 u	8 u	9 u
Change	+ 2.2 u	+ 3.2 u	- 5.4 u
After	13.2 u	11.2 u	3.6 u

Number of erasers that Corwin gave to Oscar and Andy
= ³₅ x 9 u
= 5.4 u

Number of erasers that Andy received from Corwin
= ⁴⁰₁₀₀ x 8 u
= 3.2 u

Number of erasers that Oscar received from Corwin
= 5.4 u - 3.2 u
= 2.2 u

Number of less erasers that Corwin had less than Oscar
= 13.2 u - 3.6 u 
= 9.6 u

9.6 u = 288

1 u = 288 ÷ 9.6 = 30

Number of erasers that Oscar and Corwin had
= 13.2 u + 3.6 u
= 16.8 u
= 16.8 x 30
= 504

Answer(s): 504