- #1

Alexsandro

- 51

- 0

If you have 2 dollars, 2 quarter and 3 nickels:

a) how many different sums can you pay without making change?

b) Change the quarters into dimes and answer again.

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This question is in a book and the answers are:

a)35 (0 sum being excluded);

b)23

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To the item (a), I did this way:

if it can to be used [0,1 or 2] dollars, [0,1 or 2] quarters and [0,1,2, or 3] nickels, then there are 3x3x4 = 36 - 1 = 35 different sums, excluding the 0 sum.

Is my reasoning correct?

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I don't find the answer to item (b). Could you help me ?