There were some starfruits and mangoes in Box M and Box N. In Box M, the ratio of the starfruits to the number of mangoes was 6 : 1. In Box N, the ratio of the number of starfruits to the number of mangoes was 5 : 2. There were 2 times as many fruits in Box M as in Box N. After another 72 mangoes were put into Box N, the ratio of the number of starfruits to the number of mangoes in Box N became 1 : 4. How many fruits were there in Box M?

Box M		Box N
2x7 = 14 u		1x7 = 7 u
Starfruits	Mangoes	Starfruits	Mangoes
6x2	1x2	5	2
12 u	2 u	5 u	2 u

The total number of fruits in Box M is repeated.  Make the total number of fruits in Box M the same.  LCM of 2 and 7 is 14.

The total number of fruits in Box N at first is repeated.  Make the total number of fruits in Box N the same.  LCM of 1 and 7 is 7.

	Box M		Box N
	Starfruits	Mangoes	Starfruits	Mangoes
Before	12 u	2 u	5 u	2 u
Change				+ 72
After	12 u	2 u	1x5 = 5 u	4x5 = 20 u

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

Number of mangoes put into Box N
= 20 u - 2 u
= 18 u

18 u = 72

1 u = 72 ÷ 18 = 4

Number of fruits in Box M
= 12 u + 2 u
= 14 u
= 14 x 4
= 56

Answer(s): 56