Question

4 martians, 3 plutonians and 5 jupiterians are to be seated in a row at an interplanetary conference. How many seating arrangements are possible?

Answer 1

we are given

martians =4

plutonians =3

jupiterians=5

so, total number of seats =4+3+5=12

number of seating arrangement for martians is 4!

number of seating arrangement for plutonians is 3!

number of seating arrangement for jupiterians is 5!

total number of seating arrangement is 12!

so, we get

possible seating arrangements are

$=\frac{12!}{4!3!5!}$

$=27720$.............Answer