A basketball player scores with probability 1/2 on each independent shot. Find the probability of exactly 2 scores in 4 shots.
Answer and explanation
Correct answer: C. 3/8
- Step 1: Use the binomial formula P = C(n, k) p^k (1 - p)^(n - k).
- Step 2: P = C(4, 2) x (1/2)^2 x (1/2)^2 = 6 x 1/4 x 1/4 = 3/8.
Answer
3/8.
Why not the others: '1/4' ignores the failures and the number of arrangements; '3/2' forgets the factor (1 - p) for the misses; '1/16' forgets the binomial coefficient.
Practise more Algebra, Trigonometry and Probability.
Free questions with an explanation for every one, and full timed Qatar Senior Secondary Certificate (Thanaweya) mock tests.
More Algebra, Trigonometry and Probability questions
- What is the modulus and principal argument of the complex number z = -1 + i * sqrt(3)?
- Using De Moivre's Theorem, evaluate (cos(pi/6) + i sin(pi/6))^6.
- In the binomial expansion of (2x - 1/x)^8, what is the term independent of x (the constant term)?
- Solve the trigonometric equation 2 cos^2(x) - cos(x) - 1 = 0 on the interval [0, 2pi).
- What is the sum of all three-digit positive integers that are multiples of 7?
- A committee of 4 students is to be selected at random from 6 boys and 5 girls. What is the probability that the committee contains exactly 2…