48 of these people are women. 61 of the 80 people like coffee. 8 of the men do not like coffee.
(a) Use this information to complete the frequency tree.(3)
One of the people who like coffee is chosen at random.
(b) Find the probability that this person is a woman. (2)
Mark scheme (a)
Answer
Mark
Mark scheme
32, 48, 24, 8, 37, 11
C1
starts to interpret information, eg 48 or 8 in correct place
C1
for \(80 - 48\ (= 32)\) and \(\text{``}32\text{''} - 8\ (= 24)\)
C1
completes frequency tree correctly SC: award C2 if all correct frequencies are shown as fractions of 80.
Mark scheme (b)
Answer
Mark
Mark scheme
\(\dfrac{37}{61}\)
M1
ft for \(\dfrac{a}{\text{``}61\text{''}}\) with \(a \lt \text{``}61\text{''}\) or \(\dfrac{\text{``}37\text{''}}{b}\) with \(b \gt \text{``}37\text{''}\)
A1
ft from diagram in (a)
Additional guidance
Incorrect notation with “37” and “61” can earn the method mark but not the accuracy mark.
Accept any equivalent fraction, decimal form 0.60(65...) or 0.61 or percentage form 60(.65...)% or 60% or 61%
