Tim bought 110 grey and red balloons for a party. The number of red balloons was ⁴₇ times as many as the number of grey balloons. Tim used ¹₂ times as many red balloons as grey balloons and was left with thrice as many red balloons as grey balloons. How many balloons did Tim have in the end?

	Red (1)	Grey (2)	Make b the same. (2)x3 = (3)
Before	40	70	210
Change	- 1 p	- 2 p	- 6 p
After	3 b	1 b	3 b

Number of red balloons that Tim bought at first = 4 u
Number of grey balloons that Tim bought at first = 7 u

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

11 u = 110

1 u = 110 ÷ 11 = 10

Number of red balloons at first
= 4 u
= 4 x 10
= 40

Number of grey balloons at first
= 7 u
= 7 x 10
= 70

40 - 1 p = 3 b --- (1)
70 - 2 p = 1 b --- (2)

(2)_x3
210 - 6 p = 3 b --- (3)

(3) = (1)
210 - 6 p = 40 - 1 p
6 p - 1 p = 210 - 40 
5 p = 170

1 p = 170 ÷ 5 = 34

Number of balloons that Tim used
= 1 p + 2 p
= 3 p
= 3 x 34
= 102

Number of balloons that Tim had in the end
= 110 - 102
= 8

Answer(s): 8