Page No 405:
Question 13:
Fill in the blanks in following table:
P(A) | P(B) | P(A ∩ B) | P(A ∪ B) | |
(i) |
|
|
| … |
(ii) | 0.35 | … | 0.25 | 0.6 |
(iii) | 0.5 | 0.35 | … | 0.7 |
(i) Here,
We know that 
(ii) Here, P(A) = 0.35, P(A ∩ B) = 0.25, P(A ∪ B) = 0.6
We know that P(A ∪ B) = P(A) + P(B) – P(A ∩ B)
∴0.6 = 0.35 + P(B) – 0.25
⇒ P(B) = 0.6 – 0.35 + 0.25
⇒ P(B) = 0.5
(iii)Here, P(A) = 0.5, P(B) = 0.35, P(A ∪ B) = 0.7
We know that P(A ∪ B) = P(A) + P(B) – P(A ∩ B)
∴0.7 = 0.5 + 0.35 – P(A ∩ B)
⇒ P(A ∩ B) = 0.5 + 0.35 – 0.7
⇒ P(A ∩ B) = 0.15
