The first mechanic worked for 10 hours and the second mechanic worked for 15 hours.
Step-by-step explanation:
Given,
Charges of first mechanic = $95 per hour
Charges of second mechanic = $115 per hour
Total hours = 25
Total amount charged = $2675
Let,
The number of hours worked by first mechanic = x
The number of hours worked by second mechanic = y
According to given statement;
x+y=25 Eqn 1
95x+115y=2675 Eqn 2
Multiplying Eqn 1 by 95

Subtracting Eqn 3 from Eqn 2

Dividing both sides by 20

Putting y=15 in Eqn 1

The first mechanic worked for 10 hours and the second mechanic worked for 15 hours.
Keywords: linear equation, elimination method
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Answer:
39.275
Step-by-step explanation:
the diameter of the semicircle is 10
A semicircle is half a circle, and a quarter circle is 1/4 of a circle.
Perimeter of a semicircle is ¶d/2
= 3.142 x 10/2 = 3.142 x 5 = 15.71
For 2 semicircles that will be 15.71 x 2 = 31.42
For the quarter circle, perimeter is ¶d/4 = 3.142 x 10/4 = 3.142 x 2.5 = 7.855
Total perimeter = 31.42 + 7.855 = 39.275
Answer:
Option B
Step-by-step explanation:
Here we have to apply " combination and permutation. " It is given that the drama club had to choose three booths from a selection of 9, considering the possible ways to choose so. This is a perfect example of combination. In nCr, n corresponds to 9, respectively r corresponds to 3.

Hope that helps!
Answer:
Step-by-step explanation:
11 - 19 - 4 - (-8) =
11 - 19 - 4 + 8 =
- 23 + 19 =
- 4 <===