Statisticshard · Past Paper
A bag contains 5 red and 'n' blue balls. If the probability of drawing a blue ball is double that of a red ball, find n.
A5
B10
C15
D20
✓ Correct Answer: B — 10
P(Blue) = n/(n+5). P(Red) = 5/(n+5). n/(n+5) = 2 * 5/(n+5) => n = 10.
Share this question
More from Statistics
- The median of 4, 1, 3, 2, 5 is:
- What is the first quartile (Q1) of 1, 2, 3, 4, 5?
- If a fair die is rolled once, what is the probability of getting an even number?
- A spinner has 8 equal sectors numbered 1 to 8. What is the probability of landing on a prime number?
- Find P(A union B) given the following data.