Eric, Howard and Christopher collected marbles in the ratio of 7 : 9 : 4. After Christopher gave ³₄ to Eric and Howard, Christopher had 252 less marbles than Eric. The number of marbles that Howard had increased by 30%. How many marbles did Eric and Christopher have in the end?

	Eric	Howard	Christopher
Before	7 u	9 u	4 u
Change	+ 0.3 u	+ 2.7 u	- 3 u
After	7.3 u	11.7 u	1 u

Number of marbles that Christopher gave to Eric and Howard
= ³₄ x 4 u
= 3 u

Number of marbles that Howard received from Christopher
= ³⁰₁₀₀ x 9 u
= 2.7 u

Number of marbles that Eric received from Christopher
= 3 u - 2.7 u
= 0.3 u

Number of less marbles that Christopher had less than Eric
= 7.3 u - 1 u 
= 6.3 u

6.3 u = 252

1 u = 252 ÷ 6.3 = 40

Number of marbles that Eric and Christopher had
= 7.3 u + 1 u
= 8.3 u
= 8.3 x 40
= 332

Answer(s): 332