AQA · Mathematics · 8300
GCSE Maths: Probability: not happening
Probability · AQA GCSE Maths (8300). Cards are generated from the Corbettmaths practice questions for Probability: not happening (Corbettmaths Video 250), and every card links back to the exact page it came from. Practice tests are drawn from this deck’s own cards. Source material © Corbettmaths — used with attribution.
30 flashcards · Free to study · No account needed
Study this deck
Preparing your cards…
All questions and answers
Read through the full deck, or practise recalling each answer above.
On a probability scale, what numerical value represents an event that is certain to happen?
Show answer
1 (or 100%)
On a probability scale, what numerical value represents an impossible event?
Show answer
0
What is the probability of rolling a 10 on an ordinary six-sided dice?
Show answer
0 (impossible)
What is the probability of rolling a number less than 7 on a fair six-sided dice?
Show answer
1 (certain)
What is the probability of rolling a 6 on a fair six-sided dice?
Show answer
1/6
What is the probability of rolling an odd number on a fair six-sided dice?
Show answer
1/2 (or 3/6, since there are three odd numbers: 1, 3, 5)
If there are 10 yellow counters, 5 orange counters, and 4 white counters in a bag, what is the probability of selecting an orange counter at random?
Show answer
5/19 (5 orange out of 19 total counters)
In a bag of 50 sweets where 13 are lemon flavored and the rest are strawberry, what is the probability of selecting a strawberry sweet?
Show answer
37/50 (since 50 - 13 = 37 strawberry sweets)
How many square numbers are there from 1 to 10?
Show answer
3 (the numbers 1, 4, and 9)
How many prime numbers are there from 1 to 10?
Show answer
4 (the numbers 2, 3, 5, and 7)
What is the formula for calculating the probability of an event?
Show answer
Probability = (Number of favorable outcomes) / (Total number of possible outcomes)
What is the probability of picking a green pen from a box containing 6 blue pens, 8 black pens, and 3 red pens?
Show answer
0 (or impossible). There are no green pens in the box.
How many even prime numbers are less than 20?
Show answer
One (the number 2). 2 is the only even prime number.
If the probability of choosing a yellow rose is 0.1 and the probability of choosing a white rose is 0.2, what is the probability of choosing either yellow or white?
Show answer
0.3. For mutually exclusive events, add the individual probabilities: 0.1 + 0.2 = 0.3.
If the probabilities of choosing yellow, white, and red roses are 0.1, 0.2, and unknown respectively, what is the probability of choosing a red rose?
Show answer
0.7. All probabilities must sum to 1, so P(red) = 1 - 0.1 - 0.2 = 0.7.
In a deck of 60 cards, 8 cards have a star. What is the probability of NOT picking a card with a star?
Show answer
52/60 or 13/15 (approximately 0.867). There are 52 cards without a star out of 60 total cards.
How do you calculate the probability of selecting B OR C when these are mutually exclusive outcomes?
Show answer
Add the individual probabilities: P(B or C) = P(B) + P(C).
A bag contains 400 counters. There are 92 yellow counters, and P(brown) = 0.13. How many brown counters are in the bag?
Show answer
52 brown counters. 0.13 × 400 = 52.
What is the probability of rolling less than 5 on a standard six-sided dice?
Show answer
4/6 or 2/3 (approximately 0.667). Four outcomes (1, 2, 3, 4) out of six possible outcomes.
If P(pink) = 0.15 and P(green) = 0.25 for 200 counters, and P(red) is twice P(white), what is P(red)?
Show answer
0.4. Let P(white) = x, then P(red) = 2x. Since 0.15 + 0.25 + x + 2x = 1, we get 3x = 0.6, so x = 0.2 and P(red) = 0.4.
If the probability of an event happening is p, what is the probability of it not happening?
Show answer
1 − p (since all probabilities must sum to 1)
What is the formula for expected value in a probability context?
Show answer
Multiply each outcome by its probability, then sum all products. E.g., Expected value = (value₁ × P₁) + (value₂ × P₂) + ...
If you know the total number of items and the probability of selecting one type, how do you find the count of that type?
Show answer
Multiply the total number by the probability: count = total × probability
In a probability problem, if all probabilities for mutually exclusive outcomes must sum to what value?
Show answer
1 (or 100%). All possible outcomes together have a total probability of 1.
How do you calculate expected frequency of an outcome in repeated trials?
Show answer
Multiply the probability of the outcome by the number of trials: expected frequency = probability × number of trials
If Bowl A and Bowl B each have limes and other fruit, and the probability of selecting a lime is the same from both bowls, what equation can you write?
Show answer
(limes in A)/(total in A) = (limes in B)/(total in B)
In probability profit calculations for raffles, what is the formula for profit?
Show answer
Profit = Total revenue − Total cost. Revenue comes from ticket sales; costs from prizes.
If you know the total and the probability of one part, how do you express the count of the remaining part?
Show answer
Count of remaining = Total × (1 − probability of known part). Alternatively, Total − (count of known part).
When working with ratios and probabilities together, what does the ratio tell you?
Show answer
The ratio tells you the relative proportions of each type. Convert these to fractions of the total to get probabilities.
In a probability expression problem with n black socks and 12 white socks, what is the expression for P(white)?
Show answer
12/(n + 12), where the denominator is the total number of socks.
Want to create your own cards? Create a free account. AI generation uses credits.