Abi had four boxes, J, K, L and M which contained a total of 325 mangoes. She transferred 50 mangoes from Box J to Box K, 124 mangoes from Box K to Box L and 232 mangoes from Box L to Box M. The ratio of the number of mangoes in Box J to Box K to Box L changed from  3 : 5 : 9 to 1 : 3 : 9. How many mangoes were in Box M at first?

	Make p the same (1)x3 = (3)	J (1)	K (2)	L	M
Before	9 u	3 u	5 u	9 u	?
Change 1	- 150	- 50	+ 50
Change 2			- 124	+ 124
Change 3				- 232	+ 232
After	3 p	1 p	3 p	9 p	?

3 u - 50 = 1 p --- (1)

5 u + 50 - 124 = 3 p
5 u - 74 = 3 p --- (2)

(1) _{x 3}
9 u - 150 = 3 p --- (3)

Make p the same.

(3) = (2)
9 u - 150 = 5 u - 74
9 u - 5 u = 150 - 74
4 u = 76

1 u = 76 ÷ 4 = 19

Total number of mangoes in Box J, Box K and Box L
= 3 u + 5 u + 9 u
= 17 u

Total number of mangoes in Box M at first
= 325 - 17 u
= 325 - 17 x 19
= 325 - 323
= 2

Answer(s): 2