The numbers 1, 2, 3, 4, 5, 6, 7, 8, 9 are to be arranged. How many different arrangements are possible under the condition that all odd numbers come first?
A)144
B)36
C)4
D)2880
E)576

Question

Quizplus · Accepted Answer

There are 5 odd numbers and 4 even numbers.
The odd numbers can be arranged among themselves in 5! ways.
The even numbers can be arranged among themselves in 4! ways.
So the total number of arrangements is 5! * 4! = 2880.

The Numbers 1, 2, 3, 4, 5, 6, 7, 8