Answer:
Step-by-step explanation:
Let r represent the rate charged by the first mechanic. Then 160-r is the rate charged by the second mechanic. The total of charges is ...
20r +5(160-r) = 2375
15r +800 = 2375 . . . . . . eliminate parentheses
15r = 1575 . . . . . . . . . . . . subtract 800
r = 105 . . . . . . . . . . . . . . . divide by 15. First mechanic's rate.
160-r = 55 . . . . . Second mechanic's rate
The first mechanic charged $105 per hour; the second, $55 per hour.
Answer: the rate charged per hour by the first mechanic is 105 per hour.
the rate charged per hour by the second mechanic is 55 per hour.
Step-by-step explanation:
Let x represent the rate charged per hour by the first mechanic.
Let y represent the rate charged per hour by the second mechanic.
The first mechanic worked for 20 hours, and the second mechanic worked for 5 hours. Together they charged a total of 2375. This means that
20x + 5y = 2375 - - - - - - - - - - -1
if the sum of the two rates was 160 per hour, it means that
x + y = 160
Substituting x = 160 - y into equation 1, it becomes.
20(160 - y) + 5y = 2375
3200 - 20y + 5y = 2375
- 20y + 5y = 2375 - 3200
- 15y = - 825
y = - 825/ - 15
y = 55
x = 160 - y = 160 - 55
x = 105
