Eric bought 154 yellow and brown balloons for a party. The number of brown balloons was ⁴₇ times as many as the number of yellow balloons. Eric used ¹₃ times as many brown balloons as yellow balloons and was left with twice as many brown balloons as yellow balloons. How many balloons did Eric have in the end?

	Brown (1)	Yellow (2)	Make b the same. (2)x2 = (3)
Before	56	98	196
Change	- 1 p	- 3 p	- 6 p
After	2 b	1 b	2 b

Number of brown balloons that Eric bought at first = 4 u
Number of yellow balloons that Eric bought at first = 7 u

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

11 u = 154

1 u = 154 ÷ 11 = 14

Number of brown balloons at first
= 4 u
= 4 x 14
= 56

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

56 - 1 p = 2 b --- (1)
98 - 3 p = 1 b --- (2)

(2)_x2
196 - 6 p = 2 b --- (3)

(3) = (1)
196 - 6 p = 56 - 1 p
6 p - 1 p = 196 - 56 
5 p = 140

1 p = 140 ÷ 5 = 28

Number of balloons that Eric used
= 1 p + 3 p
= 4 p
= 4 x 28
= 112

Number of balloons that Eric had in the end
= 154 - 112
= 42

Answer(s): 42