In a Combination the order doesn't matter. Wether you start with the number 1, 2, or 3  123, 132, 213, 231, 321 312 are "different numbers" but that would be the answer for a permutation case, where the order DOES matter.  Having this said, there is only ONE combination possible since either way you arrange … Read more

For every dollar there are 10 dimes. And every 20 nickels make a dollar as well.  10 dimes + 20 nickels are 30 coins, adding up to two dollars.  25 dimes ($2.50) + 15 nickels ($0.75) would make a total of 40 coins adding up to $3.25  Therefore there is a total of 25 dimes.