Number of cars sold Exam practice
20 A car manufacturer sells diesel, petrol and electric cars.
The composite bar chart shows information about sales over three years.
Key
6000
Diesel
5000
Petrol
4000
Electric
3000
2000
1000-
0
2016 2017 2018
Year
a Write down the number of diesel cars sold in 2016
b Work out the total number of petrol cars sold in the 3 years
(3 marks
c State the type of car that had the greatest increase in sales over the three years
Give a reason for your answer
(2 marks
Mark says, 'in 2018, more electric cars were sold than diesel cars. This means
the manufacturer makes more profit from the sale of electric cars than from the
sale of diesel cars
d Is Mark correct? You must justify your answer
anted from IMF Max 2018 012

Exercise: counting committees 0.0/2.0 puntos (calificable) we start with a pool of n people. a chaired committee consists of k≥1 members, out of whom one member is designated as the chairperson. the expression k(nk) can be interpreted as the number of possible chaired committees with k members. this is because we have (nk) choices for the k members, and once the members are chosen, there are then k choices for the chairperson. thus, c=∑k=1nk(nk) is the total number of possible chaired committees of any size. find the value of c (as a function of n ) by thinking about a different way of forming a chaired committee: first choose the chairperson, then choose the other members of the committee. the answer is of the form c=(α+nβ)2γn+δ. what are the values of α , β , γ , and δ ?