Posted by Lily on Saturday, September 13, 2008 at 10:02pm.
a group of friends took a bus trip. Each traveler gave the bus driver a tip using the same nine coins. the total tip was $8.41. how many dimes did the driver receive?

PLEASE HELP ME WITH MY MATH H.W.  bobpursley, Saturday, September 13, 2008 at 10:24pm
So each tip has to be some even number of cents. So divide 8.41 by the number of folks, and see if you can make that tip with nine coins. Now, notice the ones digit in the total is 1, so to divide evenly, the number of persons willhave to be X3, X7, or X9. So try the number of persons as 3, 7, 9, 13, 17, 19, 23, 27, and bingo, 29, which works to give an even number of cents per person (8.41/29=29 cents each)
so the nine coins have to make 29 cents,
You can figure out what nine coins.
group tipeach 
PLEASE HELP ME WITH MY MATH H.W.  Anon, Saturday, September 13, 2008 at 11:04pm
12 friends, 70cents each. 5 dimes and 4 nickles. 9 coins total

PLEASE HELP ME WITH MY MATH H.W.  Lily, Saturday, September 13, 2008 at 11:27pm
thank you, but how did u get that

PLEASE HELP ME WITH MY MATH H.W.  David Q, Sunday, September 14, 2008 at 7:15am
Whatever the number of friends is, it has to divide into $8.41 (i.e. 841 cents) without a remainder  so you need to find out what integers (because there can only be an integer number of friends) divide into 841. As Bob showed, that's easy: you can just do it by trial and error. You'll find that 29 divides into 841 cents to give 29 cents each. It's the only possible answer because 29 is a prime number, which means there's no other possible factorization. So... the tip is 29 cents, and each person gave that in just nine coins. I'm not familiar enough with American coinage to know how that could be done because I'm not American  but you are, so I'm afraid you'll have to do this part yourself!

PLEASE HELP ME WITH MY MATH H.W.  Anonymous, Sunday, September 14, 2008 at 2:19pm
ohhhhhhhhhh, thank you!