Question
One of the 6 letters is taken at random.
(a) Write down the probability that the letter is S.
(b) The letter is replaced and again a letter is taken at random.
This is repeated 600 times.
How many times would you expect the letter to be S?
Answer/Explanation
Ans:
(a) \(\frac{2}{6}\) oe
(b) 200 Final answer
Question
(a) A box contains 3 blue pens, 4 red pens and 8 green pens only.
A pen is chosen at random from the box.
Find the probability that this pen is green.
……………………………..………..
(b) A cube has only one of its six faces painted yellow.
This cube is rolled 240 times.
Work out the expected number of times that it lands on the yellow face.
……………………………………….
Answer/Explanation
(a)\(\frac{8}{15}\)
(b)40
Question
Simon has ten cards, numbered 1 to 10 . He chooses a card at random. Write down the probability that the number on the card is
(a) 8,
(b) 12,
(c) an odd number,
(d) not a multiple of 3.
▶️Answer/Explanation
Given that Simon has ten cards numbered 1 to 10:
Total number of possible outcomes = 10 (since there are 10 cards in total)
(a) Probability of choosing the card with number 8:
There is only 1 card numbered 8.
Number of favorable outcomes = 1
Probability = Number of favorable outcomes / Total number of possible outcomes \(=\frac{1}{10}\)
(b) Probability of choosing the card with number 12:
There is no card numbered 12.
Number of favorable outcomes = 0
Probability = Number of favorable outcomes / Total number of possible outcomes\( =\frac{0}{10}= 0\)
(c) Probability of choosing an odd number:
There are 5 odd-numbered cards (1, 3, 5, 7, 9).
Number of favorable outcomes = 5
Probability = Number of favorable outcomes / Total number of possible outcomes \(=\frac{5}{10}\)
(d) Probability of not choosing a multiple of 3:
There are 7 cards that are not multiples of 3 (1, 2, 4, 5, 7, 8, 10).
Number of favorable outcomes = 7
Probability = Number of favorable outcomes / Total number of possible outcomes \(=\frac{7}{10}\)