Handling Data 4
2 marks · NormalA two-way table shows the numbers of Year 11 students who study French and Spanish.
| French | No French | Total | |
|---|---|---|---|
| Spanish | 12 | 5 | 17 |
| No Spanish | 18 | 7 | 25 |
| Total | 30 | 12 | 42 |
A student from this group is chosen at random. Find:
The probability that the student studies both French and Spanish.
Given that a student studies French, what is the probability that they also study Spanish?
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) 12/42 = 2/7
(b) 12/30 = 0.4
Common mistakes: Incorrect denominator for conditional probability
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly gives probability as 12/42 (=2/7).
B2 (b) · 1 mark · Correctly finds conditional probability: 12/30 = 0.4.
Worked solution
a) Both French and Spanish: 12/42 = 2/7
b) Of the 30 who study French, 12 do both: 12/30 = 0.4