A fruit seller sells only lemons and pears. The ratio of lemons to pears is 3 : 4. A total of 289 fruits are added. The number of lemons becomes 4 times as many as before and the number of pears becomes 3 times as many as before. How many fruits are there in the end?

	Comparing lemons at first and in the end	Lemons	Pears	Comparing pears at first and in the end
Before	1x3 = 3 u	3 u	4 u	1x4 = 4 u
Change		+ 289
After	4x3 = 12 u	12 u	12 u	3x4 = 12 u

The number of pears at first is repeated.  Make the number of pears at first the same.  LCM of 1 and 4 is 4.

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

Number of fruits at first
= 3 u + 4 u
= 7 u

Number of fruits in the end
= 12 u + 12 u
= 24 u

Number of fruits added
= 24 u - 7 u 
= 17 u

17 u = 289

1 u = 289 ÷ 17 = 17

Number of fruits in the end
= 24 u
= 24 x 17
= 408

Answer(s): 408