There were some oranges and mangosteens in Container M and Container N. In Container M, the ratio of the oranges to the number of mangosteens was 6 : 1. In Container N, the ratio of the number of oranges to the number of mangosteens was 5 : 2. There were 3 times as many fruits in Container M as in Container N. After another 90 mangosteens were put into Container N, the ratio of the number of oranges to the number of mangosteens in Container N became 1 : 4. How many fruits were there in Container M?

Container M		Container N
3x7 = 21 u		1x7 = 7 u
Oranges	Mangosteens	Oranges	Mangosteens
6x3	1x3	5	2
18 u	3 u	5 u	2 u

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

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

	Container M		Container N
	Oranges	Mangosteens	Oranges	Mangosteens
Before	18 u	3 u	5 u	2 u
Change				+ 90
After	18 u	3 u	1x5 = 5 u	4x5 = 20 u

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

Number of mangosteens put into Container N
= 20 u - 2 u
= 18 u

18 u = 90

1 u = 90 ÷ 18 = 5

Number of fruits in Container M
= 18 u + 3 u
= 21 u
= 21 x 5
= 105

Answer(s): 105