Question

David has $1.05 in dimes and quarters. How many combinations of coins could he have?

A. 1

B. 2

C. 3

D. 5

Answer 1

Can anybody explain how to solve this?

Answer 2

1 dime is worth 10 cents.
1 quarter is worth 25 cents.
You can guess and check.
If David have 1 quarter, how many dimes would he have?

Answer 3

2 ?

Answer 4

Well yes. The answer is 2.
You can think logically as well.
A quarter is worth 25 cents, and a dime is worth 10 cents.
A quarter can only end in 5 or 0, while a dime only end in 0.
So if you have 1 quarter, the you would have 8 dimes.
There's no possible outcome with 2 quarters because .25+.25= .50, and that end in 0.
The total amount has a .05.
So the total amount of quarter must end in odd.
But .25*5 is over 1.05. So there must be less than 5 quarters.
Do you understand now?
I hope this help!

Answer 5

@GoldPhenoix I understand what you wrote, but I don't know what the answer would be

Answer 6

The answer is 2.

Answer 7

Thanks!!!