Question

The school store sells pens for $0.35 each and pencils for $0.15 each. Anthony spent $2.80 to buy a total of 12 pens and pencils. How many pens did Anthony buy?

Answer 1

Answer:

The answer to your question is Antony bought 5 pens

Step-by-step explanation:

Data

pens = p = $0.35

pencils = n = $0.15

total amount = 12

total money spent = $2.80

Process

1.- Write equations

               p  +  n  = 12                -------------- (l)

        0.35p  +  0.15n = 2.80      --------------(ll)

2.- Solve the system of equations by elimination

Multiply equation l by - 0.35

         - 0.35p - 0.35n = -4.2

           0.35p + 0.15 n = 2.8

              0      - 0.2n = -1.4

Solve for n

                         n = -1.4 / -0.2

                         n = 7      He bought 7 pencils

3.- Find the value of p

              p + 7 = 12

              p = 12 - 7

              p = 5                He bought 5 pens