Discover how to measure the chance of something happening, from coin tosses to picking cards from a deck.
Probability measures how likely an event is to happen, calculated as: Probability = (number of favorable outcomes) ÷ (total number of possible outcomes). It always falls between 0 (impossible) and 1 (certain).
A coin is tossed once. What is the probability of getting heads?
1 favorable outcome (heads) out of 2 total outcomes = 1/2
A die is rolled once. What is the probability of getting a 4?
1 favorable outcome out of 6 total outcomes = 1/6
Probability problems often involve picking an item at random from a set — like a card from a deck or a marble from a bag. Counting how many favorable items exist out of the total gives the probability.
A bag has 5 red balls and 3 blue balls. What is the probability of picking a red ball at random?
5 favorable out of 8 total = 5/8
A standard deck has 52 cards, 4 of which are Kings. What is the probability of drawing a King?
4 favorable out of 52 total = 4/52 = 1/13
1. A die is rolled once. What is the probability of getting an even number?
2. A coin is tossed once. What is the probability of getting tails?
3. A bag has 4 green balls and 6 yellow balls. What is the probability of picking a yellow ball at random?
4. A standard deck has 52 cards, 13 of which are hearts. What is the probability of drawing a heart?
5. A box has 10 tickets numbered 1 to 10. What is the probability of picking a ticket with a number greater than 7?
From Integers to Probability — the entire Class 7 Selina Concise Maths book is done. You're ready for whatever comes next!
← Back to the full map