CIE iGCSE Maths E8.2 Relative and expected frequencies Exam Style Practice Questions- Paper 2
The table shows the relative frequency of the games won by a football team.
Result of game | won | lost | drawn |
---|---|---|---|
Relative frequency | 0.1 |
The number of games lost is twice the number of games drawn.
Complete the table.
▶️ Answer/Explanation
Ans: lost 0.6, drawn 0.3
Total probability = 1 → remaining = 0.9.
Let drawn = x → lost = 2x → x + 2x = 0.9 → x = 0.3.
Thus drawn = 0.3, lost = 0.6.
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
Answer: 93 employees
Method 1: Using Proportion
1. Find the survey proportion who walk:
\(\frac{3}{40} = 0.075\) (or 7.5%)
2. Apply to total employees:
\(0.075 \times 1240 = 93\)
Method 2: Cross-Multiplication
\(\frac{3}{40} = \frac{x}{1240}\)
\(3 \times 1240 = 40 \times x\)
\(3720 = 40x\)
\(x = \frac{3720}{40} = 93\)
Verification:
• 93/1240 ≈ 0.075 (matches survey proportion)
• Both methods give consistent results