Probability Maths - Probability

Two coins are tossed simultaneously. What is the probability of getting at most one head?

In a lottery there are 10 prizes and 25 blanks. What is the probability of getting a prize?

There are 40 students in a class of whom 25 are girls and 15 are boys. The class teacher has to select one student as a class representative. He writes the name of each student on a separate card, the cards being identical. Then she puts cards in a bag and stirs them thoroughly. She then draws one card from the bag. What is the probability that the name written on the card is the name of:

1. A girl?
2. A boy?

A child has a die whose 6 faces show the letters given below:

Suppose the bulbs contain 4 defective ones. One bulb is drawn at random from the lot. What is the probability that this bulb is defective?

A lot of 20 bulbs contain 4 defective ones. One bulb is drawn at random from the lot. What is the probability that this bulb is defective?

A group consists of 12 persons, of which 3 are extremely patient, other 6 are extremely honest and rest are extremely kind. A person from the group is selected at random. Assuming that each persion is equally likely to be selected, find the probability of selecting a person who is:

1. Extermely patient.
2. Extremely kind or honest. Which of the above values you prefer more.

A letter is chosen at random from the letters of the word 'ASSOCIATION'. Find the probability that the chosen letter is a:

1. Vowel.
2. Consonant.
3. An S.

A box contains 90 discs which are numbered from 1 to 90. If one disc is drawn at random from the box, find the probability that it bears:

1. A two-digit number.
2. A perfect square number.
3. A number divisible by 5.

A game of chance consists of spinning an arrow, which comes to rest pointing at one of the number 1, 2, 3, 4, 5, 6, 7, 8 and these are equally likely outcomes. Find the probability that the arrow will point at any factor of 8.

Tickets numbered 2, 3, 4, 5, ..., 100, 101 are placed in a box and mixed thoroughly. One ticket is drawn at random from the box. Find the probability that the number on the ticket is:

1. An even number.
2. A number less than 16.
3. A number which is a perfect square.
4. A prime number less than 40.

One card is drawn from a well-shuffled deck of 52 cards. Find the probability of drawing:

1. An ace.
2. A '4' cf spades.
3. A '9' of a black suit.
4. A red king.

A box contains 25 cards numbered from 1 to 25. A card is drawn at random from the bag. Find the probability that the number on the drawn card is:

1. Divisible by 2 or 3.
2. A prime number.

Two different dice are tossed together. Find the probability that

1. The number on each die is even.
2. The sum of numbers appearing on the two dice is 5.

If the probability of winning a game is 0.7, what is the probability of losing it?

Very-Short-Answer Questions.
A coin is tossed once. What is the probability of getting a tail?

Fill in the blanks:
The sum of probability of all the outcomes of an experiment is _____.

Very-Short-Answer Questions.
A die is thrown once. Find the probability of getting:
A number greater than 2.

Fill in the blanks:
The probability of an impossible event is _____.