Problema Solution

Ricardo Gutiertz has a box of coins that he uses when playing poker with friends. The box currently contains 35 coins, consisting of pennies, dimes and quarters. The number of pennies is equal to the number of dimes, and the total value is $2.90. How many of each denomination of coin does he has?

The number of pennies which is also equal to the number of dimes is _____.

The number of quarters is _____.

Answer provided by our tutors

1 penny = 1 cent

1 dime = 10 cents

1 quarter = 25 cents

Let

x = the number of pennies

x = the number of dimes 

y = the number of quarters

The box currently contains 35 coins:

x + x + y = 35

2x + y = 35

The total value is $2.90 = 290 cents:

x + 10x + 25y = 290

We have the following system of equations:

2x + y = 35

x + 10x + 25y = 290

........

click here to see the system of equations solved for x and y

........

x = 15

y = 5

The number of pennies which is also equal to the number of dimes is 15.

The number of quarters is 5.