Data Sufficiency

Four dollar amounts, w, x, y, and z, were invested in a business. Which amount was greatest?

1) y < z < x
2) x was 25 percent of the total of the four investments.

Target question: Which amount was greatest?

Statement 1: y < z < x
We are not given any information about w.
So, it could be the case that x is the greatest, or it could be the case that w is the greatest
Since we cannot answer the target question with certainty, statement 1 is NOT SUFFICIENT

Statement 2: x was 25 percent of the total of the four investments
We have no idea about w, y or z, so we cannot tell which value is the greatest.
Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined
Statement 2 tells us that x = 25% of the total sum of the four values
Statement 1 tells us that y < z < x
So, we know that y and z both account for less than 25% of the sum of the four values.
Since the sum of percentages must add to 100%, we can see that w (the missing value) must account for more than 25% of the total value. This would make w the greatest value.
Since we can answer the target question with certainty, the combined statements are SUFFICIENT

Answer = C

Cheers,
Brent

Hi soneee,

This question came up about a week ago. Here's a slightly longer thread with some additional explanations:

https://www.beatthegmat.com/how-to-solve ... tml#685570

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