Answer: 17
21-4=17
4+17=21
21+17=38 and so on..
If duke has 5 quarters that means he has 5 dimes making a total of $1.75
if donna has 60 cents more than him she has a total of $2.35
to figure out the number of quarters she has just dived $2.35 by .25 cents
she has 9 quarters and 1 dime.