C. eight or fewer
99% means 99/100
. with 9 alarms there is no way you can trigger 8 alarms with that 99% rate
If you would like to divide 2 by 1 6/7, you can do this using the following steps:
1 6/7 = 13/7
2 / 1 6/7 = 2 / 13/7 = 2/1 / 13/7 = 2/1 * 7/13 = 14/13 = 1 1/13
The correct result would be 1 1/13.
<span>A freight train completes its journey of 150 miles 1 hour earlier if its original speed is increased by 5 miles/hour. What is the train’s original speed?
***
let x=original speed
x+5=increased speed
travel time=distance/speed
..
lcd:x(x+5)
150(x+5)-150x=x(x+5)
150x+750-150x=x^2+5x
x^2+5x-750=0
(x-25)(x+30)=0
x=25
What is the train’s original speed? 25 mph</span>
Answer:
(a) 
(b) 
Step-by-step explanation:

Take
of of each term.

For Question a

Given that x = 3, y = 4, and dx/dt = 5.

For Question b

Given that x = 4, y = 3, and dx/dt = -5.

Answer:

Step-by-step explanation:
For the random variable
we define the possible values for this variable on this case
. We know that we have 2 defective transistors so then we have 5C2 (where C means combinatory) ways to select or permute the transistors in order to detect the first defective:

We want the first detective transistor on the ath place, so then the first a-1 places are non defective transistors, so then we can define the probability for the random variable
like this:

For the distribution of
we need to take in count that we are finding a conditional distribution.
given
, for this case we see that
, so then exist
ways to reorder the remaining transistors. And if we want b additional steps to obtain a second defective transistor we have the following probability defined:

And if we want to find the joint probability we just need to do this:

And if we multiply the probabilities founded we got:
