Question

a parking meter contains dimes and nickels worth $4.85. there are 71 coins in all. Find how many of each there are. How many dimes are there? How many nickels are there?

Answer 1

Let n be the number of nickels and d be the number of dimes

There are 71 coins,

Quantity Equation

n+d=71 therefore d=71-n

The total amount of money is $4.85. Each dime is worth $0.10 and each nickel is worth $0.05. The total amount of the dimes is then 0.1d and the total amount of the nickels is 0.05n.

Value Equation

0.05n+0.1d=4.85

As we knw
d=71-n

Substitute this expression in the value equation
0.05n+0.1(71-n)=4.85

0.05n-0.1n+7.1=4.85

n=45

and from that we get

d=71-45=26