A fruit seller sells only peaches and pears. The ratio of peaches to pears is 3 : 5. A total of 336 fruits are added. The number of peaches becomes 4 times as many as before and the number of pears becomes 4 times as many as before. How many fruits are there at first?

	Comparing peaches at first and in the end	Peaches	Pears	Comparing pears at first and in the end
Before	1x3 = 3 u	3 u	5 u	1x5 = 5 u
Change		+ 336
After	4x3 = 12 u	12 u	20 u	4x5 = 20 u

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

The number of peaches at first is repeated. Make the number of peaches 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 + 20 u
= 32 u

Number of fruits added
= 32 u - 8 u 
= 24 u

24 u = 336

1 u = 336 ÷ 24 = 14

Number of fruits at first
= 8 u
= 8 x 14
= 112

Answer(s): 112