-0.272727272727272727272727272727
Answer:
0.8594
Step-by-step explanation:
Let a denote the event of forgetting to shut off machine and b be the event of being defective.
-A foreman forgets to shut off machine 55% of the time.
-If he forgets, 15% of molds are defective.
-If he does not, 3% of molds are defective.
#The probability that he forgot to shut off the machine is calculated as:

P(a and ~b)=0.55(1-0.15)=0.4675
P(~a and b) = (1-0.55)*0.03=0.0135
P(~a and ~b) = (1-0.55)*(1-0.03)=0.4365
#Conditional probability is defined as:

Hence, the probability that the foreman forgot to shut off the machine the previous night is 0.8594
Start with

We observe that both fractions are not defined if
. So, we will assume
.
We multiply both numerator and denominator of the first fraction by 3 and we sum the two fractions:

We multiply both sides by
:

We move everything to one side and solve the quadratic equation:

We check the solution:

which is true
Answer:
25 students
Step-by-step explanation:
50% of 50 is 25
50/2 = 25
4/5
just take 16/20 and divde both be 4