Answer:
11 Combination of Coins
Step-by-step explanation:
You've answered part of the question already.
I'll continue from where you stopped.
Let D represents Dime
Let N represents Nickels
The answer starts from here
Let’s start by assuming he uses only 1
quarter.
D N
7 1
6 3
5 5
4 7
3 9
That’s 5 combinations.
Notice that the sum of each row is a consecutive number.
i.e 8,9,10...
Now, let's assume he's going to get both quarters.
For Dime,he has 10/2 possible dime for a start.
For nickel, we'll start from the least possible; 0
While Dime reduces by 1, Nickel increases by 2
So, we have
D N
5 0
4 2
3 4
2 6
1 8
0 10
That's 6 combinations
Total Possible Combination = 5 + 6
Total Possible Combination = 11 Combinations
