Answer:
x = 12
Step-by-step explanation:
5x + 15 = 75
-15 -15
5x = 60
x = 12
Answer:
the first is 70 and the second is 140
Step-by-step explanation:
Answer: x = 13
Step-by-step explanation: When solving an equation like this, we are trying to get our variable which is our letter by itself.
So we first want to ask ourselves what is the 14 doing to <em>x</em>. Well, we can see that it's being added to <em>x</em> so to get <em>x</em> by itself, we will do the opposite of addition which is subtraction. So we subtract 14 from both sides of the equation.
The +14 -14 cancels out so we're left with <em>x</em> on the left.
On the right, we must subtract 14 from 27 to get 13.
So we have x = 13 which is the solution to this equation.
Answer:
a) P(t>3)=0.30
b) P(t>10|t>9)=0.67
Step-by-step explanation:
We have a repair time modeled as an exponentially random variable, with mean 1/0.4=2.5 hours.
The parameter λ of the exponential distribution is the inverse of the mean, so its λ=0.4 h^-1.
The probabity that a repair time exceeds k hours can be written as:

(a) the probability that a repair time exceeds 3 hours?

(b) the conditional probability that a repair takes at least 10 hours, given that it takes more than 9 hours?
The exponential distribution has a memoryless property, in which the probabilities of future events are not dependant of past events.
In this case, the conditional probability that a repair takes at least 10 hours, given that it takes more than 9 hours is equal to the probability that a repair takes at least (10-9)=1 hour.


115 degrees as 70+40=115 and that is equal to ?