The Post Office has stamps in the denominations 17 cents, 9 cents, and 5 cents. What is the largest amount of postage that cannot be made using these denominations?
2007-03-11 12:41:04 · 3 answers · asked by blondie 2 in Science & Mathematics ➔ Mathematics
21 cents is the largest whole number of cents which cannot me made with 5, 9, and 17 cent stamps.
Every larger whole number of cents can be made with a combination of 5, 9, and 17 cent stamps.
For example,
22 = 5 + 17
23 = 5 + 9 + 9
24 = 5 + 5 + 5 + 9
25 = 5 + 5 + 5 + 5 + 5
26 = 9 + 17
Five in a row ... just add five to get the next block, etc.
Dan
2007-03-11 12:54:11 · answer #1 · answered by ymail493 5 · 3⤊ 0⤋
There is no Largest number.
2007-03-11 12:44:41 · answer #2 · answered by richardwptljc 6 · 0⤊ 0⤋
I believe it is 21.
2007-03-11 13:00:15 · answer #3 · answered by Gnomon 6 · 0⤊ 0⤋