Bunuel wrote:

A grocer sells avocados for $1.50 each and pineapples for $2.00 each. How many avocados did the grocer sell today?

(1) The number of avocados sold today is 20 more than twice the number of pineapples sold.

(2) Today the grocer received a total of $155 from the sale of avocados and pineapples.

We'll use simple numbers to help show ourselves the logic.

This is an Alternative approach.

(1) Say 1 pineapple was sold. Then 2*1 + 20 = 22 avocados were sold.

Say 2 pineapples were sold. Then 2*2 + 20 = 24 avocados were sold.

Insufficient.

(2) Say the grocer sold as many pineapples as possible. That is, he sold 152/2 = 76 pineapples and 2 avocados.

Now, say we try to contradict this by having the grocer sell as many avocados as possible. Even without calculating, we can SEE that this gives a different solution.

Insufficient.

Combined:

So if the grocer sells p pineapples and a avocados (1) gives us a = 2p + 20 and (2) gives us 1.5a + 2p = 155.

Even without solving, we can see this is 2 distinct linear equations with 2 variables and therefore has one solution. (which happens to be p=25, a = 70)

Sufficient.

(C) is our answer.

_________________

David

Senior tutor at examPAL

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