Ibrahim and Yessica have $25 in paper money and a lot of quarters and pennies. He has 22 coins and she has 14. Their coins add up to $2.52. They ask you to guess how many quarters and how many pennies they had. WHAT VARIABLES might you need?



Answer :

Answer:

The variables are P for pennies and Q for quarters, and solving the equations we can find that they have 9 quarters and 27 pennies.

Step-by-step explanation:

We know that they have quarters and pennies, then the variables that we will use are:

P = total number of pennies

Q = total number of quarters.

Now let's solve the problem.

We know that the value of a penny is $0.01

We know that the value of a quarter is $0.25

We know that he has 22 coins, and she has 14 coins.

Then the total number of coins is 22  + 14 = 36 coins, then:

P + Q = 36

We also know that the total value of these coins is $2.52

then:

P*$0.01 + Q*$0.25 = $2.52

Then we have a system of equations:

P + Q = 36

P*$0.01 + Q*$0.25 = $2.52

To solve it, we need to start by isolate one of the variables in one of the equations, let's isolate P in the first one

P = 36 - Q

Now we can replace this in the other equation:

(36 - Q)*$0.01 + Q*$0.25 = $2.52

Now we can solve this for Q.

36*$0.01 - Q*$0.01 + Q*$0.25 = $2.52

$0.36 + Q*$0.24 = $2.52

Q*$0.24 = $2.52 - $0.36 = $2.16

Q = $2.16/$0.24 = 9

Then they have 9 quarters, and the number of pennies is given by

P = 36 - Q = 36 - 9 = 27

They have 27 pennies.