GMATBaumgartner wrote:

There are three varieties of sugar in a store. Sugar (S1) costs $6 per kilogram and sugar (S2) costs $9 per kilogram. Sugar (S1) is mixed with Sugar (S2) and a new variety of Sugar (S3) is formed. If 20 kilograms of Sugar (S3) consists of A kilogram of Sugar (S1) and B kilogram of Sugar (S2), is A > B ?

(1) A > 9

(2) The cost of 20 kilogram of Sugar (S3) is more than $150.

(1) Given: A+B = 20 kg

When A=10kg , B= 10kg

When A = 11 kg, B = 9 kg.

Hence, not sufficient.

(2) Assume cost of 20 kg = $ 150.

Then, cost of 1 kg =

\frac{150}{20}= $7.5

Hence the cost of 1 kg of S3 is $7.5.

The cost of 1 kg can also be expressed as

\frac{Total Cost}{Total Weight}or,

\frac{6A+9B}{A+B}= 7.57.5 is the weighted average between 6 and 9, and is equidistant from both 6 and 9. This means that when the cost is equal to $150, then A = B. But if it is greater than $ 150, then the balance of weighted average will shift towards B, and hence, B>A. Sufficient.

_________________

Kudos is the currency of appreciation.

You can have anything you want if you want it badly enough. You can be anything you want to be and do anything you set out to accomplish, if you hold to that desire with the singleness of purpose. ~William Adams

Many of life's failures are people who did not realize how close to success they were when they gave up. ~Thomas A. Edison

Wir müssen wissen, Wir werden wissen. (We must know, we will know.) ~Hilbert