Pierre bought 187 green and pink balloons for a party. The number of pink balloons was ⁴₇ times as many as the number of green balloons. Pierre used ¹₃ times as many pink balloons as green balloons and was left with twice as many pink balloons as green balloons. How many balloons did Pierre have in the end?

	Pink (1)	Green (2)	Make b the same. (2)x2 = (3)
Before	68	119	238
Change	- 1 p	- 3 p	- 6 p
After	2 b	1 b	2 b

Number of pink balloons that Pierre bought at first = 4 u
Number of green balloons that Pierre bought at first = 7 u

Total number of balloons at first
= 4 u + 7 u
= 11 u

11 u = 187

1 u = 187 ÷ 11 = 17

Number of pink balloons at first
= 4 u
= 4 x 17
= 68

Number of green balloons at first
= 7 u
= 7 x 17
= 119

68 - 1 p = 2 b --- (1)
119 - 3 p = 1 b --- (2)

(2)_x2
238 - 6 p = 2 b --- (3)

(3) = (1)
238 - 6 p = 68 - 1 p
6 p - 1 p = 238 - 68 
5 p = 170

1 p = 170 ÷ 5 = 34

Number of balloons that Pierre used
= 1 p + 3 p
= 4 p
= 4 x 34
= 136

Number of balloons that Pierre had in the end
= 187 - 136
= 51

Answer(s): 51