Easy to Find, a computer data base, charges $30/h during peak hours to access its records. The charge during off-peak hours is $12/h. Indigo Research was billed $876.00 last month for 40 hours of access time. Using a system of equations, find the number of hours charged for usage during peak times.

Answer 1

Let x be the number of hours charged for peak time usage.
Then the number of hours charged for off-peak time usage is 40 - x.
According to the given information, the total cost for the peak time usage is 30x, and the total cost for the off-peak time usage is 12(40 - x).
Using the system of equations, we have:
30x + 12(40 - x) = 876
30x + 480 - 12x = 876
18x + 480 = 876
18x = 876 - 480
18x = 396
x = 396/18
x = <<22=22>>22
Therefore, the number of hours charged for usage during peak times is 22. Answer: \boxed{22}.