This is a difficultly worded question- is it asking for how long it takes for the first guy to wash two cars and separately how long it takes for the second guy to wash two cars? If so, the answer is 4 and 8. If it's asking how long it takes them to band together and wash 2 cars, it will take 4 hours.
The answer to this is D !!! The last one
Answer:
Step-by-step explanation:
Answer:
Option D is correct.
Step-by-step explanation:
We have been given the rate is raised by $45
Since, if we increased mean by 45 there will be no change in number of observations and in sum because there is symmetry in the sum of observations.
So, mean will be increased by $45
And standard deviation will remain same because it means how far the term is from the mean.
Therefore, option D is correct.