Answer: 8 hours
Step-by-step explanation:
Let x be the time taken by each person to paint the fence.
Given: Tom and Becky can paint Jim's fence together in 12 hours.
Since all people paint at the same rate, then we have the following equation ;-
Thus, the time taken by each person to paint the fence alone = 24 hours
Now, the time taken by all three paint together:-
Hence, it would take 8 hours if all three paint together.
This question not incomplete
Complete Question
The life of a semiconductor laser at a constant power is normally distributed with a mean of 7,000 hours and a standard deviation of 600 hours. If three lasers are used in a product and they are assumed to fail independently, the probability that all three are still operating after 7,000 hours is closest to? Assuming percentile = 95%
Answer:
0.125
Step-by-step explanation:
Assuming for 95%
z score for 95th percentile = 1.645
We find the Probability using z table.
P(z = 1.645) = P( x ≤ 7000)
= P(x<Z) = 0.95
After 7000 hours = P > 7000
= 1 - P(x < 7000)
= 1 - 0.95
= 0.05
If three lasers are used in a product and they are assumed to fail independently, the probability that all three are still operating after 7,000 hours is calculated as:
(P > 7000)³
(0.05)³ = 0.125
15. would be 1/2 because if you simplify 16/32 to 8/16 (dividing by 2 each time), then to 4/8, then 2/4, and lastly 1/2
you really dont need to do all of that because 16/32 is already 1/2 (16 is half of
32)
16. the answer would be 7/12 because if you divide 21/36 both by 3 you get 7/12 and you cant go any more simpler.
The derivative of (x+1)^2, for this you use the chain rule, to get 2x+2.
16.4 would be the greatest and 15.6 would be the least due to 2.5% equaling 0.4 and adding and subtracting it from 16.
