I'm going to buy one-cent, two-cent, three-cent, five-cent, and ten-cent stamps. I'm going to buy four of each of two sorts, and three of each of the rest, and I have exactly enough to buy them -- just this handful of dimes. How many of each type am I going to buy?
Well, we are just making the ones column zero. So three of each of the stamps is 63 cents and we need a combination of two different stamps to make the total 70 cents. Ergo the answer is a 2 cent stamp and a 5 cent stamp.
ReplyDelete3 one-cent
4 two-cent
3 three-cent
4 five-cent
3 ten-cent
3 x 1 cent
ReplyDelete4 x 2 cent
3 x 3 cent
4 x 5 cent
3 x 10 cent
For a total of 70 cents.
Aw...too slow.
ReplyDeletequick riddle, it says you are going to buy four of each
ReplyDeletenvrmind
ReplyDeleteAndy and Jay have it right.
ReplyDeleteSince you have at least three of each stamps, you know the minimum is 63 cents. If you had one to each of the most expensive stamps, you can't get to 80 cents total, so you know the total has to be 70 cents.
The cost for the two extra stamps must be seven cents, so you have to use one more five cent stamp and one more two cent stamp.