Final answer:
The student's question about how many pennies and nickels Madi has can be solved by setting up equations based on their values and the given relationship. Calculations show that Madi has 80 pennies and 160 nickels, so the correct answer is (d).
Step-by-step explanation:
The question asks us to find the number of pennies and nickels Madi has if she has $8.80 in total, with twice as many nickels as pennies. Let's denote the number of pennies as p and the number of nickels as n. Since a penny is worth 1 cent and a nickel is worth 5 cents, we can set up two equations:
Substituting the second equation into the first, we get p + 5(2p) = 880, which simplifies to 11p = 880. Therefore, p = 880/11 = 80. Since n = 2p, we have n = 2×80 = 160.
Madi has 80 pennies and 160 nickels. Thus, the correct answer is (d) 80 pennies, 160 nickels.