Select the equation that solves this problem:

Question

Eleven coins (dimes and nickels) are worth 60 cents. How many dimes are
there?
a. 10d + 25(11 - d) = 170
b. 10d + 25(8 - d) = 170
c. 10d + 5(8 - d) = 60
d. 10d + 5(11 - d) = 60

Answer 1

ten nickels is 50 cents ... plus a dime is 60 cents

Answer 2

Note that all the equations start with 10d, indicating that you are adding up the value of the coins.
So right away you know it's C or D
Since there are 11 coins, if there are d dimes, then there are 11-d nickels.
So, D