A fruit seller sells only pears and persimmons. The ratio of pears to persimmons is 1 : 3. A total of 153 fruits are added. The number of pears becomes 4 times as many as before and the number of persimmons becomes 3 times as many as before. How many fruits are there in the end?

	Comparing pears at first and in the end	Pears	Persimmons	Comparing persimmons at first and in the end
Before	1x1 = 1 u	1 u	3 u	1x3 = 3 u
Change		+ 153
After	4x1 = 4 u	4 u	9 u	3x3 = 9 u

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

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

Number of fruits at first
= 1 u + 3 u
= 4 u

Number of fruits in the end
= 4 u + 9 u
= 13 u

Number of fruits added
= 13 u - 4 u 
= 9 u

9 u = 153

1 u = 153 ÷ 9 = 17

Number of fruits in the end
= 13 u
= 13 x 17
= 221

Answer(s): 221