How do you this math?

Question

5. If P(A) = 0.4, P(B) = 0.2, and P(A and B) = 0.18, what is P(A or B)?
A. 0.38
B. 0.42
C. 0.56
D. 0.58
E. 0.61

6. If P(A) = 0.28, P(B) = 0.41, and P(A and B) = 0.16, what is P(A or B)?
A. .69
B. .53
C. .57
D. .44
E. .03

7. If P(A) = 0.27, P(B) = 0.47, and P(A and B) = 0.16, what is P(A or B)?
A. .38
B. .42
C. .56
D. .58
E. .61

8. If P(A) = 0.7, P(B) = 0.4, and P(A or B) = 0.8, what is P(A and B)?
A. .3
B. .4
C. .5
D. .8
E. .6

Answer 1

5. If P(A) = 0.4, P(B) = 0.2, and P(A and B) = 0.18, what is P(A or B)?
Sol. use the formula
P(A or B) = P(A) + P(B) - P(A and B)
=0.4 +0.2 -0.18
=0.42...............................Ans(B)


6. If P(A) = 0.28, P(B) = 0.41, and P(A and B) = 0.16, what is P(A or B)?
Sol. use the formula
P(A or B) = P(A) + P(B) - P(A and B)
=0.28 +0.41 -0.16
=0.53...............................Ans(B)


7. If P(A) = 0.27, P(B) = 0.47, and P(A and B) = 0.16, what is P(A or B)?
Sol. use the formula
P(A or B) = P(A) + P(B) - P(A and B)
=0.27 +0.47 -0.16
=0.58...............................Ans(D)


8. If P(A) = 0.7, P(B) = 0.4, and P(A or B) = 0.8, what is P(A and B)?
Sol. use the formula
P(A or B) = P(A) + P(B) - P(A and B)
0.8=0.7 +0.4 - P(A and B)
P(A and B)=0.7 +0.4 -0.8
=0.3...............................Ans(A)