Answer:
The plumber worked 50 hours, and his assistant worked 25 hours.
Step-by-step explanation:
Since a plumber and his assistant work together to replace the pipes in an old house, and the plumber charges $ 30 an hour for his own labor and $ 20 an hour for his assistant's labor, and the plumber works twice as long as his assistant on this job, and the labor charge on the final bill is $ 2000, to determine how long did the plumber and his assistant work on this job the following calculation must be performed:
40 x 30 + 20 x 20 = 1200 + 400 = 1600
50 x 30 + 25 x 20 = 1500 + 500 = 2000
Therefore, the plumber worked 50 hours, and his assistant worked 25 hours.
Answer:
C. f(-1) =12
Step-by-step explanation:
f(x)= 3x^2+9
Let x=-1
f(-1) = 3(-1)^2 +9
= 3(1)+9
= 3+9
= 12
f(-1) =12
Answer:
x = 27
Step-by-step explanation:
Given
= 3
Multiply both sides by 9 to clear the fraction
x = 9 × 3 = 27
<h3>
Answer: C) 2.47 cm</h3>
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Explanation:
We have 81 cm^3 of clay. Divide this among the 20 students and each gets 81/20 = 4.05 cm^3 of clay
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The volume of a cone is
V = (1/3)*pi*r^2*h
Solving for h gets us
3V = pi*r^2*h
(3V)/(pi*r^2) = h
h = (3V)/(pi*r^2)
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The diameter is 2.5 cm which cuts in half to 1.25 cm, so this is the radius.
We'll plug this radius in, along with V = 4.05 and pi = 3.14
h = (3V)/(pi*r^2)
h = (3*4.05)/(3.14*(1.25)^2)
h = 2.4764
This value is approximate. Rounding down to the nearest hundredth gets us 2.47
We round down because rounding up to 2.48 will lead to a volume larger than 4.05
