David bought 144 white and brown balloons for a party. The number of brown balloons was ³₅ times as many as the number of white balloons. David used ¹₄ times as many brown balloons as white balloons and was left with twice as many brown balloons as white balloons. How many balloons did David have in the end?

	Brown (1)	White (2)	Make b the same. (2)x2 = (3)
Before	54	90	180
Change	- 1 p	- 4 p	- 8 p
After	2 b	1 b	2 b

Number of brown balloons that David bought at first = 3 u
Number of white balloons that David bought at first = 5 u

Total number of balloons at first
= 3 u + 5 u
= 8 u

8 u = 144

1 u = 144 ÷ 8 = 18

Number of brown balloons at first
= 3 u
= 3 x 18
= 54

Number of white balloons at first
= 5 u
= 5 x 18
= 90

54 - 1 p = 2 b --- (1)
90 - 4 p = 1 b --- (2)

(2)_x2
180 - 8 p = 2 b --- (3)

(3) = (1)
180 - 8 p = 54 - 1 p
8 p - 1 p = 180 - 54 
7 p = 126

1 p = 126 ÷ 7 = 18

Number of balloons that David used
= 1 p + 4 p
= 5 p
= 5 x 18
= 90

Number of balloons that David had in the end
= 144 - 90
= 54

Answer(s): 54