How Many Pens Did Marco Buy?

Question

marco bought pens & pencils with his companys name & website address to give away to people at a festival. he bought a total of 300 pens & pencils together & spent $62.50. if pencils cost $0.15 each & pens cost $0.25 each, how many pens did marco buy?

Answer 1

Let's set equation using variables.

x = number of pens he bought

y = number of pencils he bought

Total 300 pens and pencils -> x + y = 300

Total costs -> 0.25*x + 0.15*y = 62.50

We need to find the value of "x", so lets substitute y with x to make equation with only one variable x.

y = 300 - x

0.25*x + 0.15*(300-x) = 62.50

0.25x + 45 - 0.15x = 62.50

0.1x = 17.5

x = 175

Answer : 175 pens

Hope this is helpful ! :)