A pencil costs $0.27 and a pen costs $0.32. You buy six pencils and the total cost is $4.18. How many pens did you buy?

2 Answers
Mar 25, 2018

8 pens.

Explanation:

Let's model our situation with an equation.

We're going to have two variables, one for pencils and one for pens.

Let p stand for the number of pencils bought, n stand for the number of pens bought, and C be the total cost (in dollars):

C=0.27p+0.32n, as we're given the individual costs of pencils and pens.

We are given our cost, C=$4.18. Now, we're also told we buy 6 pencils, so p=6. Plug these into our equation:

4.18=0.27(6)+0.32n

What we're really being asked is to solve for n, so let's do that.

4.18=1.62+0.32n

0.32n=4.18-1.62=2.56

n=2.56/0.32=8

So, we bought 8 pens.

Mar 25, 2018

8 pens

Explanation:

say i bought x pencils and y pens
so x pencils cost 0.27 *x dollars
similarly , y pens cost 0.32 * y dollars

total cost = cost of x pencils +cost of y pens
4.18 = 0.27 * 6 + 0.32*y
so y = (4.18 -1.62)/0.32 =8

so i bought 8 pens