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:
A. x=0 and x=4
Step-by-step explanation:
The roots of a quadratic function are the x intercepts of the parabola. In this case, the roots are 0 and 4 because the parabola intercepts the x axis twice in these points.
Your answer is A. x=0 and x=4
Hope I helped!
Answer:
c) 50
Step-by-step explanation:
We have been given that the mean life of a particular brand of light bulb is 1200 hours. About 95% of this brand of bulbs will last between 1100 and 1300 hours.
We will use z-score formula to solve our given problem.
, where,
,
,
,

We know that 95% of data points lies within two standard deviation of mean, so 1100 will correspond to a z-score of -2 and 1300 will correspond to a z-score of 2.




We can use sample score 1300 and get same answer as:




Therefore, the standard deviation of the light bulbs’ life is 50 years.
Answer:
(1,4)
Step-by-step explanation:

(x,y)→(1,4)
The answer is
a1 =-2/9
a2 =4/3
a3 =6