A fruit seller sells only kiwis and guavas. The ratio of kiwis to guavas is 1 : 3. A total of 32 fruits are added. The number of kiwis becomes 3 times as many as before and the number of guavas becomes 3 times as many as before. How many fruits are there in the end?

	Comparing kiwis at first and in the end	Kiwis	Guavas	Comparing guavas at first and in the end
Before	1x1 = 1 u	1 u	3 u	1x3 = 3 u
Change		+ 32
After	3x1 = 3 u	3 u	9 u	3x3 = 9 u

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

The number of kiwis at first is repeated. Make the number of kiwis 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
= 3 u + 9 u
= 12 u

Number of fruits added
= 12 u - 4 u 
= 8 u

8 u = 32

1 u = 32 ÷ 8 = 4

Number of fruits in the end
= 12 u
= 12 x 4
= 48

Answer(s): 48