. How many dimes are there in the bank

Question

A piggy bank contains Nickles dimes and quarters. There are three times as many dimes as quarters and six more nickels and dimes The total value of all the coins is $5.90 . How many dimes are there in the bank

Answer 1

Here's what we know:

3q = d

d + 6 = n

.05n + .1d + .25q = 5.9

 

Since we have values for our variables, let's plug them in:

.05(d + 6) + .1(3q) + .25q = 5.9

.05((3q) + 6) + .1(3q) + .25q = 5.9

.15q + .3 + .3q +.25q = 5.9

simplify and then isolate q:

.7q + .3 = 5.9

.7q = 5.6

q = 8

 

Now that we know our quarters, we can solve for dimes:

3*8 = d

24 = d

 

And to check our answer, we also need to know our nickels:

24 + 6 = n

30 = n

 

Time to check:

30 * .05 + 24 * .1 + 8 *.25 = 5.9

1.5 + 2.4 + 2 = 5.9

5.9 = 5.9