Both dice even — Probability Aptitude Question
Both dice even: Two dice are thrown. What is the probability that both show even numbers? Answer and worked solution on CodeKairo.
- Topic: Probability
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 50 seconds
Question
Two dice are thrown. What is the probability that both show even numbers?
Options
- 1/6
- 1/4
- 1/3
- 1/2
Show the answer and the worked solution
Correct answer: B. 1/4
Worked solution
- P(even on one die) = 3/6 = 1/2.
- Both: 1/2 × 1/2 = 1/4.
Answer: 1/4.
The idea
The dice are independent, so multiply. Counting favourable outcomes gives 9 out of 36, which is the same 1/4.
Shortcut. Both dice must succeed at a half-chance each, so the answer must sit below 1/2: 1/2 × 1/2 = 1/4.
Common trap. "1/2" — giving the probability for one die and forgetting that both must be even.