<h2>
Answer:</h2>
a)
The probability that both televisions work is: 0.42
b)
The probability at least one of the two televisions does not work is:
0.5833
<h2>
Step-by-step explanation:</h2>
There are a total of 9 televisions.
It is given that:
Three of the televisions are defective.
This means that the number of televisions which are non-defective are:
9-3=6
a)
The probability that both televisions work is calculated by:

( Since 6 televisions are in working conditions and out of these 6 2 are to be selected.
and the total outcome is the selection of 2 televisions from a total of 9 televisions)
Hence, we get:

b)
The probability at least one of the two televisions does not work:
Is equal to the probability that one does not work+probability both do not work.
Probability one does not work is calculated by:

and the probability both do not work is:

Hence, Probability that atleast does not work is:
0.5+0.0833=0.5833
Answer:

Step-by-step explanation:
<u>Use identities to set the equation up as a quadratic</u>

<u>Make the substitution u=cos(x) and solve the quadratic</u>
<u />


Hence, 
Answer:
4.8 minutes
Step-by-step explanation:
Using the given hint, working together, the amount of floor mopped in 1 minute is ...
1/8 + 1/12 = 3/24 +2/24 = 5/24 . . . . jobs/minute
The reciprocal of that is the rate in terms of minutes per job. Thus the entire job takes 24/5 = 4.8 minutes.
Answer:
-m^2 |n|^3 sqrt(n)
Step-by-step explanation:
-sqrt( m^4n^7)
We know that sqrt(ab) = sqrt(a) sqrt(b)
-sqrt(m^4) sqrt(n^7)
The sqrt(m^4) = m^2
The sqrt(n^7) = sqrt(n^6) sqrt(n) = |n|^3 sqrt(n) We take the absolute value because if n is negative, n^6 is postive, but n^3 is negative
-sqrt(m^4) sqrt(n^7)
-m^2 |n|^3 sqrt(n)