The office supply superstore sells pens for 60 cents each and pencils for 40 cents each. Diane purchased a total of 17 items
(pens and pencils) for $8.20. How many pens did Diane
purchase?
A 5
В 7
C 10
D
12

Diane purchased 7 pens and 10 pencils.

The selling price of pens is 60 cents each ($0.6) while it is 40 cents each for pencils ($0.4).

Let x represent the number of pens bought and y represent the number of pencils.

Since a total of 17 items was bought for $8.20, hence:

x + y = 17   (1)

0.6x + 0.4y = 8.2   (2)

Solving equations 1 and 2 gives:

x = 7, y = 10

Therefore Diane purchased 7 pens and 10 pencils.

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Option B.   7

Step-by-step explanation:

In order to solve this question we first have to find out what is the difference between the prices of a pen and a pencil. SO we get...

60 - 4- = 20 cents

Now if we were to assume that all 17 items were pencils then Diane would pay

17 x 0.40 = $6.8

But then he pays 8.2-6.8 = $1.4 less than he should be.

If we substitute one pencil with a pen the total will increase by 20 cents. From here we can easily get the number of pens by doing the following...

1.4 / 0.2 = 7 pens

Therefore option B is the right answer.

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step-by-step explanation: