Simon bought 140 brown and green balloons for a party. The number of green balloons was ³₇ times as many as the number of brown balloons. Simon used ¹₄ times as many green balloons as brown balloons and was left with twice as many green balloons as brown balloons. How many balloons did Simon have in the end?

	Green (1)	Brown (2)	Make b the same. (2)x2 = (3)
Before	42	98	196
Change	- 1 p	- 4 p	- 8 p
After	2 b	1 b	2 b

Number of green balloons that Simon bought at first = 3 u
Number of brown balloons that Simon bought at first = 7 u

Total number of balloons at first
= 3 u + 7 u
= 10 u

10 u = 140

1 u = 140 ÷ 10 = 14

Number of green balloons at first
= 3 u
= 3 x 14
= 42

Number of brown balloons at first
= 7 u
= 7 x 14
= 98

42 - 1 p = 2 b --- (1)
98 - 4 p = 1 b --- (2)

(2)_x2
196 - 8 p = 2 b --- (3)

(3) = (1)
196 - 8 p = 42 - 1 p
8 p - 1 p = 196 - 42 
7 p = 154

1 p = 154 ÷ 7 = 22

Number of balloons that Simon used
= 1 p + 4 p
= 5 p
= 5 x 22
= 110

Number of balloons that Simon had in the end
= 140 - 110
= 30

Answer(s): 30