A fruit seller sells only peaches and lemons. The ratio of peaches to lemons is 4 : 5. A total of 252 fruits are added. The number of peaches becomes 3 times as many as before and the number of lemons becomes 3 times as many as before. How many fruits are there in the end?

	Comparing peaches at first and in the end	Peaches	Lemons	Comparing lemons at first and in the end
Before	1x4 = 4 u	4 u	5 u	1x5 = 5 u
Change		+ 252
After	3x4 = 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 peaches at first is repeated. Make the number of peaches at first the same. LCM of 1 and 4 is 4.

Number of fruits at first
= 4 u + 5 u
= 9 u

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

Number of fruits added
= 27 u - 9 u 
= 18 u

18 u = 252

1 u = 252 ÷ 18 = 14

Number of fruits in the end
= 27 u
= 27 x 14
= 378

Answer(s): 378