Question

Ryan bought several pens at Staples, for 60 cents each. Spending the same amount of money at Rite Aid, Ryan then bought some pens that cost 80 cents each. In all, 42 pens were bought. How many pens did Ryan buy at Rite Aid? 3.

Answer 1

Answer:

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Step-by-step explanation:

x= number of pens bought at Walgreens

y= number of pens bought at Bookstore

x+y=42  (total number of pens bought was 42)

60x = 80y      (60x is the total amount of money he spent on pens at Walgreens and 80y is the total amount of money he spent at the Bookstore.  Since it says that he spent the same amount of money at each store 60x is then equal to 80y)

This equation can then be simplified to 3x = 4y by dividing both sides by 20.

Convert the equation x+y=42 into y=42-x by subtracting both sides of the equation by x.

Then substitute y into the second equation so you have

3x = 4(42-x)

3x = 168 - 4x

7x = 168

x=24

Then we plug x back into the equation x+y=42 to solve for y.

x+y=42

24+y=42

y=18

So bought 24 pens at Walgreens and 18 pens at the Bookstore.