4.01: Permutations and committee selections
(a) (i)[1]
A 6-digit number is to be formed from the digits \(1,2,3,4,5,6,7,8,9\). No digit may be used more than once. Find how many 6-digit numbers can be formed when there are no further restrictions.
See the official mark scheme below.
(a) (ii)[2]
Find how many such 6-digit numbers include the digit \(4\).
See the official mark scheme below.
(b)[3]
A class contains 10 girls and 12 boys. A group of 6 students is to be selected. There must be at least 2 girls and at least 2 boys in the group. Find the number of different selections that can be made.
See the official mark scheme below.
