A coin is tossed live times. What is the probability that there is at the least one tail?
Correct answer: A. 31/32
- A. 31/32
- B. 1/16
- C. 1/2
- D. 1/32
Explanation
For five fair tosses, the complement of at least one tail is getting no tails, meaning five heads, with probability (1/2)^5 = 1/32. Therefore, P(at least one tail) = 1 - 1/32 = 31/32. The likely mistake is choosing 1/32, which is the probability of five heads, not the probability of at least one tail.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? [email protected]
About Ratio and Proportion
Ratios compare quantities in the same units, while proportions state that two ratios are equal. Problems cover simplification, division in a given ratio, direct and inverse variation, scale, and missing terms, with attention to the difference between a ratio and a fraction representing part of a whole.
Practise Arithmetic
1,060 free Arithmetic MCQs from Mathematics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Mathematics questions like this
Mathematics is on 76 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Ratio and Proportion questions
If a number is chosen at random from the set {1, 2, 3, ...., 100}, then the probability that the chosen number is a perfect cube is___________?
Out of first 20 natural numbers, one number is selected at random. The probability that it is either an even number or a prime number is_____________?
If two dice are thrown together, the probability of getting an even number on one die and an odd number on the other is__________?
The probability that a number selected at random from the first 50 natural numbers is a composite number is__________?
A total of 3000 chocolates were distributed among 120 boys and girls such that each boy received 2 chocolates and each girl received 3 chocolates. Find the respective number of boys and girls?
Rs. 6000 is lent out in two parts. One part is lent at 7% p.a simple interest and the other is lent at 10% p.a simple interest. The total interest at the end of one year was Rs. 450. Find the ratio of the amounts lent at the lower rate and higher rate of interest?