A batch of cookies was divided amomg 6 tins: 2/3 of all the cookies were placed in either the blue or the green tin, and the rest were placed in the red tin. If 1/4 of all the cookies were placed in the blue tin, what fraction of the cookies that were placed in the other tins were placed in the green tin Answers:
A) 15 / 2
B) 9 / 4
C) 5 / 9
D) 5 / 7
E) 9 / 7

Rationale: this will help reduce the number of variables you have to deal with : g + b = 2 / 3 r = 1 / 6 b = 1 / 4 we can solve for g which is 5 / 12 what fraction ( let it equal x ) of the cookies that were placed in the other tins were placed in the green tin ? so . . x * ( g + r ) = g x * ( 5 / 12 + 1 / 6 ) = 5 / 12 x = 5 / 7 answer : d
Answer: D