A fruit seller sells only guavas and persimmons. The ratio of guavas to persimmons is 2 : 5. A total of 154 fruits are added. The number of guavas becomes 4 times as many as before and the number of persimmons becomes 2 times as many as before. How many fruits are there at first?

	Comparing guavas at first and in the end	Guavas	Persimmons	Comparing persimmons at first and in the end
Before	1x2 = 2 u	2 u	5 u	1x5 = 5 u
Change		+ 154
After	4x2 = 8 u	8 u	10 u	2x5 = 10 u

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

The number of guavas at first is repeated. Make the number of guavas 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
= 8 u + 10 u
= 18 u

Number of fruits added
= 18 u - 7 u 
= 11 u

11 u = 154

1 u = 154 ÷ 11 = 14

Number of fruits at first
= 7 u
= 7 x 14
= 98

Answer(s): 98