Tina had four containers, S, T, U and V which contained a total of 271 pears. She transferred 29 pears from Container S to Container T, 80 pears from Container T to Container U and 120 pears from Container U to Container V. The ratio of the number of pears in Container S to Container T to Container U changed from  3 : 7 : 10 to 1 : 4 : 9. How many pears were in Container V at first?

	Make p the same (1)x4 = (3)	S (1)	T (2)	U	V
Before	12 u	3 u	7 u	10 u	?
Change 1	- 116	- 29	+ 29
Change 2			- 80	+ 80
Change 3				- 120	+ 120
After	4 p	1 p	4 p	9 p	?

3 u - 29 = 1 p --- (1)

7 u + 29 - 80 = 4 p
7 u - 51 = 4 p --- (2)

(1) _{x 4}
12 u - 116 = 4 p --- (3)

Make p the same.

(3) = (2)
12 u - 116 = 7 u - 51
12 u - 7 u = 116 - 51
5 u = 65

1 u = 65 ÷ 5 = 13

Total number of pears in Container S, Container T and Container U
= 3 u + 7 u + 10 u
= 20 u

Total number of pears in Container V at first
= 271 - 20 u
= 271 - 20 x 13
= 271 - 260
= 11

Answer(s): 11