Question:

A random variable X has the following probability distribution
\(X = x\)\(1\)\(2\)\(3\)\(4\)\(5\)\(6\)\(7\)\(8\)
\(P(X = x)\)\(0.15\)\(0.23\)\(0.10\)\(0.12\)\(0.20\)\(0.08\)\(0.07\)\(0.05\)

For the events \(E = \{X\text{ is a prime number}\}\), \(F = \{X < 4\}\), \(P(E\cup F)\) is

Show Hint

List the values in each event, add their probabilities and subtract the overlap.
Updated On: Oct 1, 2026
  • \(0.5\)
  • \(0.77\)
  • \(0.35\)
  • \(0.75\)
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is D

Solution and Explanation

Step 1: Understanding the Concept:
For two events, \(P(E \cup F) = P(E) + P(F) - P(E \cap F)\).

Step 2: Find the events.
\(E\) (prime numbers in 1 to 8): \(\{2, 3, 5, 7\}\). \(F\) (\(X < 4\)): \(\{1, 2, 3\}\). \(E\cap F = \{2, 3\}\).

Step 3: Add the probabilities.
\(P(E) = 0.23 + 0.10 + 0.20 + 0.07 = 0.60\).
\(P(F) = 0.15 + 0.23 + 0.10 = 0.48\).
\(P(E\cap F) = 0.23 + 0.10 = 0.33\).

Step 4: Combine.
\[ P(E\cup F) = 0.60 + 0.48 - 0.33 = 0.75 \]

Final Answer:
\(P(E\cup F) = 0.75\), option (D). \[ \boxed{0.75} \]
Was this answer helpful?
0
0