Logan has $3.15 worth of dimes and quarters. He has twice as many dimes as quarters. Determine the number of dimes and the number of quarters that Logan has

Answer 1

The number of dimes can be represented by x and the number of quarters can be represented by y.

We know that x = 2y because there are twice as many dimes as quarters

We also know that $0.10x + $0.25y = $3.15

Therefore we can solve the system of equations through the substitution or elimination method. In this scenario I think the substitution method is easier.

Replacing x with 2y in our second equation yields...

0.10(2y) + 0.25(y) = 3.15

.2y + .25y = 3.15

.45y = 3.15

y= 7

Using our answer and plugging into the first equation...

x=2y

x = 2(7)

x=14

Answer 2

Hi Tilewa,

Logan has $3.15 worth of dimes and quarters. He has twice as many dimes as quarters. Determine the number of dimes and the number of quarters that Logan has

You'll need two equations, one is about the value of the coins, the other is about the number of coins.

0.05N + 0.10D = _______

N + D = _________

Then the system of equations can be solved by using the substitution or elimination method.

It is also convenient to think of the value in pennies rather than dollars. For example $3.15 is 315 pennies (cents).

Enjoy