12 dimes is 120 cents and 2 quarters is 50 cents that perfectly gives us 170 cents. As worded if he has 11 Dimes and the rest is quarters and we want 170 cents then it's impossible. 11 dimes is going to be 110 cents plus 2 quarters is 160 cents or plus 3 quarters is going to be 185 cents. therefore you are either short or over the money.
