Question

The probability of a student scoring 75% in class work is 0.64, and the probability of a student scoring 85% is 0.45.

Event A: The student scores 75%.
Event B: The student scores 85%.

The probability of a student scoring 85% in class work, given that they have already scored 75% in class work, is 0.55. The probability of a student scoring 75% in class work, given that they have already scored 85% in class work, is 1.
Which statement is true?

Answer 1

So basically, if a student scored 85 %, it sure scored 75 % too

So the true statement based on the scenario is : Event A and B are not independent because P(A|B) ≠ P (A)

hope this helps

Answer 2

Answer: The probability of a student scoring 75%, given that they have already scored  85% in class work is 1.

Step-by-step explanation: Given,

$P(A)=0.64$

and

$P(B)=0.45$.

Also,

If the student already scored 85%, the it is sure that he/she will definitely score 75%. Hence, the statement that the probability of a student scoring 75% in a class work, given that they already scored 85% is 1 is a true statement.

So, the second statement is true.