Which system of equations best represents the situation?

The correct answer is (a).

Step-by-step explanation:

Nickels are 5-cents coins

Quarters are 25-cents coins

1 dollar = 100 cents

N represents the number of nickels and;

Q represents the number of quarters.

The system of simultaneous equations is:

N + Q = 35 ... (i)

N + Q = $5.15 ... (ii)

Simplifying further by multiplying (ii) with 100 throughout gives:

N + Q = 35 ... (i)

5N + 25Q = $515 ... (ii)

You can rearrange it to:

N = 35 - Q ... (i)

5N + 25Q = $515 ... (ii)

So (a) is the correct answer.