A fruit seller sells only mangosteens and lemons. The ratio of mangosteens to lemons is 3 : 5. A total of 323 fruits are added. The number of mangosteens becomes 4 times as many as before and the number of lemons becomes 3 times as many as before. How many fruits are there at first?

	Comparing mangosteens at first and in the end	Mangosteens	Lemons	Comparing lemons at first and in the end
Before	1x3 = 3 u	3 u	5 u	1x5 = 5 u
Change		+ 323
After	4x3 = 12 u	12 u	15 u	3x5 = 15 u

The number of lemons at first is repeated.  Make the number of lemons at first the same.  LCM of 1 and 5 is 5.

The number of mangosteens at first is repeated. Make the number of mangosteens at first the same. LCM of 1 and 3 is 3.

Number of fruits at first
= 3 u + 5 u
= 8 u

Number of fruits in the end
= 12 u + 15 u
= 27 u

Number of fruits added
= 27 u - 8 u 
= 19 u

19 u = 323

1 u = 323 ÷ 19 = 17

Number of fruits at first
= 8 u
= 8 x 17
= 136

Answer(s): 136