Raman and Sanjay are members of a quiz team which has 9 members in total. Two photographs of the quiz team are to be taken.
For the second photograph, the members will stand in two rows, with 5 in the back row and 4 in the front row.
(c) In how many different ways can the 9 members be divided into a group of 5 and a group of 4?
(d) For a random division into a group of 5 and a group of 4, find the probability that Raman and Sanjay are in the same group as each other.
A bag contains 12 marbles, each of a different size. 8 of the marbles are red and 4 of the marbles are blue.
How many different selections of 5 marbles contain at least 4 marbles of the same colour?
A committee of 6 people is to be chosen from 9 women and 5 men.
(a) Find the number of ways in which the 6 people can be chosen if there must be more women than men on the committee.
The 9 women and 5 men include a sister and brother.
(b) Find the number of ways in which the committee can be chosen if the sister and brother cannot both be on the committee.
Mr and Mrs Ahmed with their two children, and Mr and Mrs Baker with their three children, are visiting an activity centre together. They will divide into groups for some of the activities.
(a) In how many ways can the 9 people be divided into a group of 6 and a group of 3?
(b) 5 of the 9 people are selected at random for a particular activity. Find the probability that this group of 5 people contains all 3 of the Baker children.
In a music competition, there are 8 pianists, 4 guitarists and 6 violinists. 7 of these musicians will be selected to go through to the final.
How many different selections of 7 finalists can be made if there must be at least 2 pianists, at least 1 guitarist and more violinists than guitarists?