There were some mangosteens and starfruits in Box B and Box C. In Box B, the ratio of the mangosteens to the number of starfruits was 5 : 1. In Box C, the ratio of the number of mangosteens to the number of starfruits was 5 : 3. There were 3 times as many fruits in Box B as in Box C. After another 56 starfruits were put into Box C, the ratio of the number of mangosteens to the number of starfruits in Box C became 1 : 2. How many fruits were there in Box C in the end?

Box B		Box C
3x8 = 24 u		1x8 = 8 u
Mangosteens	Starfruits	Mangosteens	Starfruits
5x4	1x4	5	3
20 u	4 u	5 u	3 u

The total number of fruits in Box B is repeated.  Make the total number of fruits in Box B the same.  LCM of 3 and 6 is 24.

The total number of fruits in Box C at first is repeated.  Make the total number of fruits in Box C the same.  LCM of 1 and 8 is 8.

	Box B		Box C
	Mangosteens	Starfruits	Mangosteens	Starfruits
Before	20 u	4 u	5 u	3 u
Change				+ 56
After	20 u	4 u	1x5 = 5 u	2x5 = 10 u

Number of mangosteens in Box C remains unchanged.  Make the number of mangosteens in Box C the same.  LCM of 5 and 1 is 5.

Number of starfruits put into Box C
= 10 u - 3 u
= 7 u

7 u = 56

1 u = 56 ÷ 7 = 8

Number of fruits in Box C in the end
= 5 u + 10 u
= 15 u
= 15 x 8
= 120

Answer(s): 120