Final answer:
There is no combination of two coins that adds up to exactly 30 cents when one of them is not a nickel.
Step-by-step explanation:
If we want to find a combination of two coins that adds up to 30 cents, and one of them is not a nickel, we can rule out option a) Quarter and nickel. This is because if we use a quarter and a nickel, we would have 25 cents + 5 cents = 30 cents, which is not the desired amount.
Options b) Dime and nickel and c) Two dimes both add up to 15 cents. Since we need a combination that adds up to 30 cents, we can eliminate these options as well.
The only remaining option is d) Quarter and dime. This combination adds up to 25 cents + 10 cents = 35 cents, which is greater than 30 cents. Therefore, there is no combination of two coins that adds up to exactly 30 cents when one of them is not a nickel.