I do not know how to solve these Questions

A) When Mr. Brown cashed his cheque, the absent-minded teller gave him as many cents as he should have dollars, and as many dollars as he should have cents. Equally absent-minded Mr. Brown left with the cash without noticing the discrepancy. It was only after he spent 5 cents that he noticed now he had twice as much money as he should. What was the amount of his cheque? (Hint: Formulate the problem so that it is a Linear Diophantine equation). B Answer the following questions. a) Let A and B be finite sets with | A|=7 and | B|=3. Find the number of distinct surjective functions that can be defined from A onto B. b) Find the number of permutations of the digits 1 through 9 in which none of the blocks 32,54 and 178 appears