AQA GCSE · Question 01 · Statistical Measures and Calculations
A fair coin is tossed four times. Circle the probability of getting 'tails' on all 4 tosses.
Answer options:
A.
1/2
B.
1/4
C.
1/8
D.
1/16
How to approach this question
To find the probability of multiple independent events happening, you multiply their individual probabilities. The probability of getting a 'tail' on one toss of a fair coin is 1/2. Since the coin is tossed four times, you need to multiply this probability by itself four times.
Full Answer
D.1/16✓ Correct
The probability of a single event (getting tails) is P(T) = 1/2. Since the four tosses are independent events, the probability of getting tails on all four tosses is the product of the individual probabilities: P(T and T and T and T) = P(T) × P(T) × P(T) × P(T) = (1/2) × (1/2) × (1/2) × (1/2) = 1/16.
Common mistakes
✗ Adding the probabilities instead of multiplying them.\n✗ Confusing the number of outcomes (2) with the probability (1/2).\n✗ Calculating the probability for the wrong number of tosses.
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