Answer:
It is C. and btw........... DON'T TRUST LINKS!!
Answer: 
Step-by-step explanation:
Let A = he known the answer then A' = he guess the answer.
B = he answered it correctly
As per given , we have



By Bayes theorem , we have

The probability that the student knows the answer given that he answered it correctly is
.
A- none because they are parallel lines
Answer:
He received 10 dimes and 15 quarters.
Step-by-step explanation:
Dimes = $0.10
Quarters = $0.25
Variable x = dimes
Variable y = quarters
Create a pair of linear equations:
0.10x + 0.25y = 4.75
x + y = 25
Isolate any variable, using an equation of your choice:
x + y = 25
x = 25 - y
Plug in this new value of x into the other equation:
0.10(25 - y) + 0.25y = 4.75
Use the distributive property:
2.5 - 0.10y + 0.25y = 4.75
Combine like terms:
2.5 + 0.15y = 4.75
Isolate variable y:
0.15y = 2.25
y = 15
Plug in the value of y into any equation:
x + y = 25
x + 15 = 25
Isolate variable x:
x = 10