Probability - OCR test questions - OCR

1

Which phrase best describes the probability that someone you know wins the lottery jackpot next week?

Impossible

Even chance

Very unlikely

2

Which of the following is NOT a measure of probability?

Improper fraction

Decimal

Percentage

3

The probability of Paul being late for work is 0.55. What is the probability that he will be on time?

0.45

Cannot be calculated

4

What is the probability of selecting a vowel from the word MATHEMATICS?

\[\frac{4}{11}\]

\[\frac{7}{11}\]

\[\frac{3}{11}\]

5

What effect does increasing the number of trials have on relative frequency?

It becomes more reliable as an estimate of probability

It becomes more difficult to calculate

It becomes less reliable as an estimate of probability

6

The probability of a seed developing into a plant is 0.32. If 1000 seeds are used, how many would be expected to develop into a plant?

320

7

A word is selected at random from a book. The number of letters it contains is counted and written down. This is repeated 50 times. Words containing fewer than 3 letters are ignored.

3 letters = 19

4 letters = 12

5 letters = 10

6 letters = 4

7 letters = 5

What is the relative frequency of selecting a word with more than 5 letters?

\[\frac{9}{50}\]

\[\frac{10}{50}\]

\[\frac{19}{50}\]

8

Two dice are thrown and the scores are added together. What is the probability of scoring a total of 5?

\[\frac{5}{36}\]

\[\frac{1}{9}\]

\[\frac{1}{6}\]

9

What are the missing probabilities on the tree diagram?

Tree diagrams showing probability of getting red or green in the bag or box

10

50 pupils are questioned about playing the piano and violin. 37 play the piano. 38 play the violin. 28 pupils play both the violin and the piano. How many pupils play only the violin?