Luis, Riordan and Clark collected buttons in the ratio of 7 : 7 : 10. After Clark gave ⁴₅ to Luis and Riordan, Clark had 102 less buttons than Luis. The number of buttons that Riordan had increased by 40%. How many buttons did Luis and Clark have in the end?

	Luis	Riordan	Clark
Before	7 u	7 u	10 u
Change	+ 5.2 u	+ 2.8 u	- 8 u
After	12.2 u	9.8 u	2 u

Number of buttons that Clark gave to Luis and Riordan
= ⁴₅ x 10 u
= 8 u

Number of buttons that Riordan received from Clark
= ⁴⁰₁₀₀ x 7 u
= 2.8 u

Number of buttons that Luis received from Clark
= 8 u - 2.8 u
= 5.2 u

Number of less buttons that Clark had less than Luis
= 12.2 u - 2 u 
= 10.2 u

10.2 u = 102

1 u = 102 ÷ 10.2 = 10

Number of buttons that Luis and Clark had
= 12.2 u + 2 u
= 14.2 u
= 14.2 x 10
= 142

Answer(s): 142