CIE iGCSE Maths E8.2 Relative and expected frequencies Exam Style Practice Questions- Paper 2
Question
A company surveys $40$ of its employees.
In the survey, $3$ employees say they walk to work.
The company has a total of $1240$ employees.
Find the expected number of employees in the company who walk to work.
▶️Answer/Explanation
$93$
3 out of 40 employees walk to work.
The company has a total of 1240 employees.
$
\frac{3}{40} = \frac{x}{1240}
$
\( x \) is the expected number of employees who walk to work.
$
3 \times 1240 = 40 \times x
$
$
3720 = 40x
$
$
x = \frac{3720}{40}
$
$
x = 93
$
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