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. A) 16 hours B) 18 hours C) 22 hours D) 24 hours

Respuesta :

Let x be the amount of peak time and y be the amount of off-peak time.

30x + 12y = 876.00

x + y = 40

Lets multiply the second equation by 12.

12x + 12y = 480

We can now subtract the two equations from each other to cancel out the y term.

30x + 12y = 876

12x + 12y = 480

18x + 0 = 396

Next, we can solve for x.

18x = 396

x = 22

Lastly, we can plug this value into one of the equations to solve for y.

22 + y = 40

y = 18

So, the number of peak hours was 22 and the number of off-peak hours was 18. The answer is C.