7 7/8= 63/8
3 1/4= 13/4
63/8 -13/4 we bring to the same denominator
(63-26)/8= 37/8
Answer: the rate of the jet in still air is 685 mph and the rate of the jetstream is 75 mph
Step-by-step explanation:
Let x represent the rate of the jet in still air.
Let y represent the rate of the jet jetstream.
Distance = speed × time
Flying against the jetstream, a jet travels 3050 miles in 5 hours. This means that the total speed of the jet would be (x - y) mph. Therefore,
3050 = 5(x - y)
3050/5 = x - y
x - y = 610 - - - - - - - - - - - - - -1
Flying with the jetstream, the same jet travels 3800 miles in 4 hours. This means that the total speed of the jet would be (x + y) mph. Therefore,
3800 = 4(x + y)
3800/5 = x + y
x + y = 760 - - - - - - - - - - - - - -2
Adding equation 1 to equation 2, it becomes
2x = 1370
x = 1370/2 = 685mph
Substituting x = 685 into equation 1, it becomes
685 - y = 610
y = 685 - 610 = 75mph
Answer:
(d-5)
Step-by-step explanation:
we know that
The phrase"five fewer than d days" is equal to subtract 5 from the number d
so
d minus 5-----> (d-5)
Using the binomial distribution, it is found that there is a 0.857 = 85.7% probability that at least 2 of the rolls come up as a 3 or a 4.
For each die, there are only two possible outcomes, either a 3 or a 4 is rolled, or it is not. The result of a roll is independent of any other roll, hence, the <em>binomial distribution</em> is used to solve this question.
Binomial probability distribution
The parameters are:
- x is the number of successes.
- n is the number of trials.
- p is the probability of a success on a single trial.
In this problem:
- There are 9 rolls, hence
.
- Of the six sides, 2 are 3 or 4, hence

The desired probability is:

In which:

Then



Then:


0.857 = 85.7% probability that at least 2 of the rolls come up as a 3 or a 4.
For more on the binomial distribution, you can check brainly.com/question/24863377
Bruh i hate plato so much