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There is typically a question (six sub-questions) about probability trees and two-way tables in the examination. These questions lead to questions that require understanding of conditional probability.
In these practice exams, it is Question Three.
Practice Exam 1 (Coffee)
Practice Exam 1 (Coffee)
91267-exm-1.pdf91267-qop-1.pdfQUESTION THREE
QUESTION THREE
When customers order a takeaway coffee with milk (either lattes, cappuccinos or flat whites), some ask for soy milk.
Half of the takeaway coffees with milk are flat whites, and 30% are cappuccinos.
Customers ask for soy milk:
· in a takeaway cappuccino 10% of the time;
· in a takeaway latte 6% of the time; and
· in a takeaway flat white 5% of the time.
(a) If a customer orders a takeaway coffee with milk, calculate the probability that it is a flat white with soy milk.
(b) Calculate the probability that a randomly selected takeaway coffee with milk uses soy milk.
(c) Oscar does not like making takeaway lattes with soy milk.
What is the probability that the next takeaway coffee with milk is not a latte with soy milk?
(d) Over one weekend, 25 takeaway coffees with soy milk are sold.
Estimate the number of these which are cappuccinos.
(e) Records also show that 21% of all takeaway coffees with milk are a “flat white with sugar”.
One of the least common drinks is a “takeaway flat white with soy milk no sugar”. Only one in 200 takeaway coffees with milk are ordered this way.
(i) Calculate the proportion of takeaway flat white with soy milk that have sugar.
(ii) Calculate the proportion of takeaway flat whites with cow milk that have sugar.
Now try other practice exams: Resources
Now try other practice exams: Resources
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