Question 3 - A-Level Maths

Exam Board	CAIE
Module	S1 (Statistics 1)
Year	2016
Session	November
Topic	Permutations & Arrangements
Type	Digit arrangements forming numbers

3 Numbers are formed using some or all of the digits 4, 5, 6, 7 with no digit being used more than once.

Show that, using exactly 3 of the digits, there are 12 different odd numbers that can be formed.
Find how many odd numbers altogether can be formed.