There were some mangoes and persimmons in Box X and Box Y. In Box X, the ratio of the mangoes to the number of persimmons was 6 : 1. In Box Y, the ratio of the number of mangoes to the number of persimmons was 5 : 2. There were 3 times as many fruits in Box X as in Box Y. After another 39 persimmons were put into Box Y, the ratio of the number of mangoes to the number of persimmons in Box Y became 1 : 3. How many fruits were there in Box X?

Box X		Box Y
3x7 = 21 u		1x7 = 7 u
Mangoes	Persimmons	Mangoes	Persimmons
6x3	1x3	5	2
18 u	3 u	5 u	2 u

The total number of fruits in Box X is repeated.  Make the total number of fruits in Box X the same.  LCM of 3 and 7 is 21.

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

	Box X		Box Y
	Mangoes	Persimmons	Mangoes	Persimmons
Before	18 u	3 u	5 u	2 u
Change				+ 39
After	18 u	3 u	1x5 = 5 u	3x5 = 15 u

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

Number of persimmons put into Box Y
= 15 u - 2 u
= 13 u

13 u = 39

1 u = 39 ÷ 13 = 3

Number of fruits in Box X
= 18 u + 3 u
= 21 u
= 21 x 3
= 63

Answer(s): 63