Zara had four boxes, D, E, F and G which contained a total of 206 mangoes. She transferred 17 mangoes from Box D to Box E, 39 mangoes from Box E to Box F and 88 mangoes from Box F to Box G. The ratio of the number of mangoes in Box D to Box E to Box F changed from  3 : 6 : 11 to 1 : 5 : 7. How many mangoes were in Box G at first?

	Make p the same (1)x5 = (3)	D (1)	E (2)	F	G
Before	15 u	3 u	6 u	11 u	?
Change 1	- 85	- 17	+ 17
Change 2			- 39	+ 39
Change 3				- 88	+ 88
After	5 p	1 p	5 p	7 p	?

3 u - 17 = 1 p --- (1)

6 u + 17 - 39 = 5 p
6 u - 22 = 5 p --- (2)

(1) _{x 5}
15 u - 85 = 5 p --- (3)

Make p the same.

(3) = (2)
15 u - 85 = 6 u - 22
15 u - 6 u = 85 - 22
9 u = 63

1 u = 63 ÷ 9 = 7

Total number of mangoes in Box D, Box E and Box F
= 3 u + 6 u + 11 u
= 20 u

Total number of mangoes in Box G at first
= 206 - 20 u
= 206 - 20 x 7
= 206 - 140
= 66

Answer(s): 66