Answer:
42
Step-by-step explanation:
3 x 7 x 2 =
= 21 x 2
= 42
Given:
A figure in which a transversal line intersect the two parallel lines.
To find:
The missing value for the equation 
Solution:
In the given figure, the two parallel lines are line ED and line AB, and CD is the transversal line.
Angle BPC and angle BPD lie on a straight line CD. So,
(Supplementary angles)
Angle APD and angle BPD lie on a straight line AB. So,
(Supplementary angles)
Therefore, the required complete equations are and .
Price of boots is represented as x, price of tennis shoes is represented as y.
x-y=44.38
x+y=196.12
Isolate x. (Or y, if you wanted to)
x=y+44.38
x=196.12-y
Set them equal to each other.
y+44.38=196.12-y
Solve for y. Then plug it in to either of the two original equations to find x.
x=120.24
y=75.86
Note: This is assuming that the boots are more expensive than the tennis shoes. If the tennis shoes are more expensive than the boots, then the prices would be switched. I didn't find this clear in your question.
Answer:
The complete question is:
At a university, 13% of students smoke.
a) Calculate the expected number of smokers in a random sample of 100 students from this university:
b) The university gym opens at 9 am on Saturday mornings. One Saturday morning at 8:55 am there are 27 students outside the gym waiting for it to open. Should you use the same approach from part (a) to calculate the expected number of smokers among these 27 students?
Part a is easy, because is a random sample, we can expect that just 13% of these 100 students to be smokers, and 13% of 100 is 13, so we can expect 13 of those 100 students to be smokers.
b) This time we do not have a random sample, our sample is a sample of 15 students who go to the gym in the early morning, so our sample is biased. (And we do not know if this bias is related to smoking or not, and how that relationship is), so we can't use the same approach that we used in the previous part.
