Sean, Oliver and Clifford collected buttons in the ratio of 12 : 5 : 7. After Clifford gave ⁴₅ to Sean and Oliver, Clifford had 448 less buttons than Sean. The number of buttons that Oliver had increased by 100%. How many buttons did Sean and Clifford have in the end?

	Sean	Oliver	Clifford
Before	12 u	5 u	7 u
Change	+ 0.6 u	+ 5 u	- 5.6 u
After	12.6 u	10 u	1.4 u

Number of buttons that Clifford gave to Sean and Oliver
= ⁴₅ x 7 u
= 5.6 u

Number of buttons that Oliver received from Clifford
= ¹⁰⁰₁₀₀ x 5 u
= 5 u

Number of buttons that Sean received from Clifford
= 5.6 u - 5 u
= 0.6 u

Number of less buttons that Clifford had less than Sean
= 12.6 u - 1.4 u 
= 11.2 u

11.2 u = 448

1 u = 448 ÷ 11.2 = 40

Number of buttons that Sean and Clifford had
= 12.6 u + 1.4 u
= 14 u
= 14 x 40
= 560

Answer(s): 560