A fruit seller sells only kiwis and mangosteens. The ratio of kiwis to mangosteens is 2 : 5. A total of 77 fruits are added. The number of kiwis becomes 2 times as many as before and the number of mangosteens becomes 2 times as many as before. How many fruits are there in the end?

	Comparing kiwis at first and in the end	Kiwis	Mangosteens	Comparing mangosteens at first and in the end
Before	1x2 = 2 u	2 u	5 u	1x5 = 5 u
Change		+ 77
After	2x2 = 4 u	4 u	10 u	2x5 = 10 u

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

The number of kiwis at first is repeated. Make the number of kiwis at first the same. LCM of 1 and 2 is 2.

Number of fruits at first
= 2 u + 5 u
= 7 u

Number of fruits in the end
= 4 u + 10 u
= 14 u

Number of fruits added
= 14 u - 7 u 
= 7 u

7 u = 77

1 u = 77 ÷ 7 = 11

Number of fruits in the end
= 14 u
= 14 x 11
= 154

Answer(s): 154