A rabbit on a controlled diet is fed daily 300 grams of

A rabbit on a controlled diet is fed daily 300 grams of a mixture of two foods, food x and food y. Food X contains 10 percent protein and food Y contains 15 percent protein. If the rabbit's diet provides exactly 38 grams of protein daily, how many grams of food X are in the mixture?

A) 100
B) 140
C) 150
D) 160
E) 200

Use W.A ---

a)     Protein % in 300 gm mix = 38 *100/300 = 38/3

b)     x/y = (15 – (38/3) ) / (38/3   -  10)

x/y = 7/8

c)     Now : x + y = 300. Hence x = 140

Ans : B