Individual : They can either buy one $20 pizza and one $10 pizza (area will be then 15^2 + 10^2 = 325) or can buy 3 $10 pizzas (area will be 100*3 = 300).

Pooled Money : Area will be greater when they can buy 3 $20 pizzas. All other combinations of pizzas will have lesser area. Hence area will be 3*(15^2) = 675

Difference would be (675 - 650) = 25.

Whats the OA?

Word Problems definitely come up on the GMAT. You might want to spend some time looking at Translation tables and refreshing on the key phrases (i.e. "less than", "is the equivalent of", "the sum of", etc.)

The small has an area of 100, and costs $10.

The larger has an area of 225, and costs $20.

One friend with $30 can either buy 3 small's, or 1 large and 1 small.

3 small's would be 300 of pizza.

1 large + 1 small would be 225 + 100 = 325 of pizza, so this is clearly preferable.

So the most that one of the friends could get if they bought individually would be 325 of pizza (or 650 for both people).

If they pooled their money, they would have $60, which would purchase 3 large's, or 225 x 3 = 675.

675 - 650 = 25 difference.

Got it 25, thats an easy one!
Would like to get these in my CAT

VivianKerr wrote:Word Problems definitely come up on the GMAT. You might want to spend some time looking at Translation tables and refreshing on the key phrases (i.e. "less than", "is the equivalent of", "the sum of", etc.)

The small has an area of 100, and costs $10.

The larger has an area of 225, and costs $20.

One friend with $30 can either buy 3 small's, or 1 large and 1 small.

3 small's would be 300 of pizza.

1 large + 1 small would be 225 + 100 = 325 of pizza, so this is clearly preferable.

So the most that one of the friends could get if they bought individually would be 325 of pizza (or 650 for both people).

If they pooled their money, they would have $60, which would purchase 3 large's, or 225 x 3 = 675.

675 - 650 = 25 difference.

Thanks Vivian. This is the right answer!