A fruit seller sells only chikoos and passion fruits. The ratio of chikoos to passion fruits is 2 : 3. A total of 36 fruits are added. The number of chikoos becomes 4 times as many as before and the number of passion fruits becomes 3 times as many as before. How many fruits are there at first?

	Comparing chikoos at first and in the end	Chikoos	Passion Fruits	Comparing passion fruits at first and in the end
Before	1x2 = 2 u	2 u	3 u	1x3 = 3 u
Change		+ 36
After	4x2 = 8 u	8 u	9 u	3x3 = 9 u

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

The number of chikoos at first is repeated. Make the number of chikoos at first the same. LCM of 1 and 2 is 2.

Number of fruits at first
= 2 u + 3 u
= 5 u

Number of fruits in the end
= 8 u + 9 u
= 17 u

Number of fruits added
= 17 u - 5 u 
= 12 u

12 u = 36

1 u = 36 ÷ 12 = 3

Number of fruits at first
= 5 u
= 5 x 3
= 15

Answer(s): 15