Question
If a random variable x has the probability distribution array |c|c|c|c|c|c|c|c|c| x & 0 & 1 & 2 & 3 & 4 & 5 & 6 & 7 \\ P(x) & 0 & 2k & k & 3k & 2k^ 2 & 2k & k^ 2 +k & 7k^ 2 \\ array then P(3 < x 6) is equal to
JEE Main
Mathematics
Probability
2026
JEE Main 2026 (22 January Shift 1)
JEE Main Mathematics Question (2026) — Solution
Options
- A. 0.64
- B. 0.22
- C. 0.33
- D. 0.34
Answer
C. 0.33
Step-by-step solution
Sum of all probabilities = 1 0 + 2k + k + 3k + 2k^2 + 2k + (k^2+k) + 7k^2 = 1 10k^2 + 9k - 1 = 0. (10k-1)(k+1) = 0 k = 1 10 (rejecting k = -1). P(3 = 2k^2 + 2k + k^2 + k = 3k^2 + 3k = 3(0.01) + 3(0.1) = 0.33.
Related: Mathematics — Probability · All PYQ Banks