Eric, Oliver and Clifford collected buttons in the ratio of 8 : 8 : 9. After Clifford gave ⁴₅ to Eric and Oliver, Clifford had 210 less buttons than Eric. The number of buttons that Oliver had increased by 80%. How many buttons did Eric and Clifford have in the end?

	Eric	Oliver	Clifford
Before	8 u	8 u	9 u
Change	+ 0.8 u	+ 6.4 u	- 7.2 u
After	8.8 u	14.4 u	1.8 u

Number of buttons that Clifford gave to Eric and Oliver
= ⁴₅ x 9 u
= 7.2 u

Number of buttons that Oliver received from Clifford
= ⁸⁰₁₀₀ x 8 u
= 6.4 u

Number of buttons that Eric received from Clifford
= 7.2 u - 6.4 u
= 0.8 u

Number of less buttons that Clifford had less than Eric
= 8.8 u - 1.8 u 
= 7 u

7 u = 210

1 u = 210 ÷ 7 = 30

Number of buttons that Eric and Clifford had
= 8.8 u + 1.8 u
= 10.6 u
= 10.6 x 30
= 318

Answer(s): 318