There were brown, pink and gold balls in a jar. Sean put another 10 brown balls and 15 gold balls in the jar, then the ratio of the number of pink balls to the number of gold balls became 5 : 2. Then, he doubled the number of brown balls and removed 23 gold balls. The ratio of the number of brown balls to pink balls became 2 : 1. He counted and found that there were a total of 113 balls left in the jar. Find the number of brown balls that he had in the end.

	Brown balls	Pink balls	Gold balls	Total
Before	5 u - 10	5 u	2 u - 15
Change 1	+ 10		+ 15
After 1	1x5 = 5 u	5 u	2 u
Change 2	+ 1x5 = 5 u		- 23
After 2	2x5 = 10 u	1x5 = 5 u	2 u - 23	113

The number of pink balls remains unchanged. Make the number of pink balls the same. LCM of 1 and 5 is 5.

Total number of balls in the end
= 10 u + 5 u + 2 u - 23
= 17 u - 23

17 u - 23 = 113
17 u = 113 + 23
17 u = 136

1 u = 136 ÷ 17 = 8

Number of brown balls in the end
= 10 u 
= 10 x 8
= 80

Answer(s): 80