Judging from the OA, I've added some key text below

BTGmoderatorLU wrote:
A certain recipe calls for 2 cups of sugar and 3 1/2 cups of flour. What is the ratio of sugar to flour in this recipe?

A. 3/10
B. 2/5
C. 4/7
D. 4/5
E. 6/7

The OA is C

A certain recipe calls for 2 cups of sugar and 3 1/2 cups of flour
So sugar/flour = 2/3.5
Check answer choices . . . . not there.

Looks like we need to create a ratio that's EQUIVALENT to 2/3.5
Multiply top and bottom by 2 to get the EQUIVALENT ratio of 4/7
Check answer choices . . . . the answer is C

Cheers,
Brent

Hi All,

We're told that a certain recipe calls for 2 cups of sugar and 3 1/2 cups of flour. We're asked for the ratio of sugar to flour in this recipe. This question can be solved in a couple of different ways. The answer choices are sufficiently 'spread out' that we can actually answer this question with a little math and some logic.

IF... the ratio was 2 cups sugar to 4 cups flour, then the ratio would be 1:2
However, it's NOT 4 cups of flour - it's a bit less (3.5 cups), thus the ratio is a little bit bigger than 1/2 (remember: ratios increase if the first number gets bigger OR the second number gets smaller). There's only one answer that's a LITTLE more than 1/2 (two of the answers are a LOT bigger than 1/2)...

Final Answer: C

GMAT assassins aren't born, they're made,
Rich

BTGmoderatorLU wrote:Source: Princeton Review

A certain recipe calls for 2 cups of sugar and 3 1/2 cups of flour. What is the ratio of flour in this recipe?

A. 3/10
B. 2/5
C. 4/7
D. 4/5
E. 6/7

The OA is C

2/(3.5) = 4/7

Answer: C