Calculate probability of simple events using classical probability theory, building on the foundation from earlier classes.
P(event) = (favourable outcomes) / (total possible outcomes), where all outcomes are equally likely.
A bag has 4 red, 5 blue, 3 green balls. Find the probability of drawing a green ball.
3/12=1/4
A card is drawn from a deck of 52. Find the probability of drawing a face card (J, Q, K).
12/52=3/13
A bag has 7 red, 5 blue, 3 green balls. Find the probability of drawing a green ball.
3/15=1/5
P(not E) = 1 − P(E). For events involving two dice or coins, listing all outcomes systematically avoids errors.
Two dice are thrown. Find the probability that the sum is 7.
Favourable: (1,6)(2,5)(3,4)(4,3)(5,2)(6,1) = 6 outcomes; total=36; P=6/36=1/6
The probability of an event is 0.35. Find the probability of its complement.
1-0.35=0.65
Two dice are thrown. Find the probability that the sum is 10.
Favourable: (4,6)(5,5)(6,4)=3 outcomes; total=36; P=3/36=1/12
1. A bag has 6 red, 4 blue balls. Find the probability of drawing a red ball.
2. A card is drawn from a deck of 52. Find the probability of drawing an ace.
3. Two dice are thrown. Find the probability that the sum is 8.
4. The probability of rain is 0.4. Find the probability it does not rain.
5. A die is rolled. Find the probability of getting a number less than 4.
6. A bag has 9 red, 6 blue balls. Find the probability of drawing a blue ball.
7. A card is drawn from a deck of 52. Find the probability of drawing a queen.
8. Two dice are thrown. Find the probability that the sum is 9.
9. The probability of passing an exam is 0.75. Find the probability of failing.
10. A die is rolled. Find the probability of getting a number greater than 2.
From Real Numbers to Probability — the entire Class 10 Maths board syllabus is done. Best of luck in your board exams!
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