GMAT: Questions

The best way to solve this problem is to translate into algebra, and then to combine the equations.

Let b be the cost, in dollars of a bagel. Let c be the cost, in dollars, of a coffee.

2

b

+

c

=

2.60

-

(

b

+

c

=

1.65)

b

=

0.95

A bagel and a coffee cost

$1.65

can be translated as

b

+

c

=

1.65

Two bagels and a coffee cost

$2.60

can be translated as

2

b

+

c

=

2.60

If you subtract the first equation from the second equation, you

get:

So now we know the price of a bagel. But that is NOT what the question is asking for. It's asking for the price of a coffee (Notice that choice (E) - $0.95, is the price of a bagel - a choice included to trap the test taker who is not paying attention.) In order to find the price of a coffee, we can now use the first equation, which is

So a coffee costs $0.70, which is choice (C). So now we know the price of a bagel. But that is NOT what the question is asking for. It's asking for the price of a coffee (Notice that choice (E) - $0.95, is the price of a bagel - a choice included to trap the test taker who is not paying attention.) In order to find the price of a coffee, we can now use the first equation, which is

b

+

c

=

1.65.

b

+

0.95

=

1.65,

b

=

1.65

-

0.95

=

0.70.

So a coffee costs $0.70, which is choice (C).