Answer:
The principal for the account is $375.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:

In which E is the amount of interest earned, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
The interest earned after 1 year is $12 .If the interest rate is 3.2% for account (A).
This means, respectively, that 
We want to find P.




The principal for the account is $375.
If he uses 1 quarter, he has 40 cent left to make.He can do that in two ways, by using 2 dimes andall four nickels, or all 3 dimes snd 2 nickels.That's 2 ways.
If he uses both quarters, he has 15 cent left to make.He can do that in two ways by using 1 dime and 1 nickel,or no dimes and 3 nickels.That's 2 more ways. So there are four ways to make 65 cents.
A decade is 10 years which means 1/5 is 2 years. thus making 2/5 4 years.