Gabriel, Dylan and Chen collected buttons in the ratio of 7 : 10 : 4. After Chen gave ⁴₅ to Gabriel and Dylan, Chen had 207 less buttons than Gabriel. The number of buttons that Dylan had increased by 25%. How many buttons did Gabriel and Chen have in the end?

	Gabriel	Dylan	Chen
Before	7 u	10 u	4 u
Change	+ 0.7 u	+ 2.5 u	- 3.2 u
After	7.7 u	12.5 u	0.8 u

Number of buttons that Chen gave to Gabriel and Dylan
= ⁴₅ x 4 u
= 3.2 u

Number of buttons that Dylan received from Chen
= ²⁵₁₀₀ x 10 u
= 2.5 u

Number of buttons that Gabriel received from Chen
= 3.2 u - 2.5 u
= 0.7 u

Number of less buttons that Chen had less than Gabriel
= 7.7 u - 0.8 u 
= 6.9 u

6.9 u = 207

1 u = 207 ÷ 6.9 = 30

Number of buttons that Gabriel and Chen had
= 7.7 u + 0.8 u
= 8.5 u
= 8.5 x 30
= 255

Answer(s): 255