Question

A customer paid a total of $16 for 74 copies at a print shop. Some of the copies were black-and-white copies, and the rest were color copies.



Each black-and-white copy cost $0.15.

Each color copy cost $0.29.

Which system of equations can be used to find `b`, the number of black-and-white copies, and `c`, the number of color copies that the customer paid for at the print shop? solve it and tell me why

Answer 1

The two equations that can be used to find `b` and `c` are:

1) b + c = 74 (total number of copies)
2) 0.15b + 0.29c = 16 (total cost of copies)

To solve this system of equations, we can use the substitution method. We can rearrange equation 1 to solve for `b` in terms of `c`:

b = 74 - c

Then, we substitute this expression for `b` into equation 2:

0.15(74 - c) + 0.29c = 16
11.1 - 0.15c + 0.29c = 16
0.14c = 4.9
c = 35

Now that we have found `c` to be 35, we can substitute this value back into the expression we found for `b` in terms of `c`:

b = 74 - 35
b = 39

Therefore, the customer paid for 39 black-and-white copies and 35 color copies at the print shop.