Answer:
There are 72 dimes having a total value of $7.2.
Step-by-step explanation:
Let the number of dimes be 'd', nickels be 'n' and quarters be 'q'.
Given:
Number of dimes is three times quarters
Number of nickels is four less than twice the number of dimes.
Total amount in the piggy bank is $20.20
Now, as per question:
Number of dimes is three times quarters
Framing in equation form, we get:
Number of nickels is four less than twice the number of dimes.
Framing in equation form, we get:
Now, value of 1 dime in dollars is 0.1.
Value 'd' dimes = $0.1d ----------(A)
Value of 1 quarter = $0.25
Value of 'q' quarters = $0.25q ----------(B)
Value of 1 nickel = $0.05
Value of 'n' nickels = $0.05n ----------(C)
Now, total amount is equal to the sum of all the amounts of each type of coin.
So, adding equations (A), (B) and (C) and equating to 20.20, we get:
Now, using equations (1) and (2), the above equation can be rewritten as:
So, there are 72 dimes in the piggy bank.
Total value of 72 dimes = 72(0.1) = $7.2