Question

double decker minibus has 10 seats in the lower deck and 12 seats in upper deck find the number of ways of arranging 22 persons in the bus if four children's wants to go to the upper deck and three old
people can't go to the upper deck​

Answer 1

Answer:

I hope I help you.........

Answer 2

Given:

Total number of seats = 22

number of seats in lower deck = 10

number of seats in upper deck = 12

And 4 children want to go to the upper deck,

3 old people can't go to the upper deck

To find:

We have to find the number of ways of arranging the people in the bus with above conditions

Solutions:

Lower deck: 10 seats: _ _ _ _ _ _ _ + 3 old people

Upper deck: 12 seats: _ _ _ _ _ _ _ _ + 4 children

Now out of 22 people 3 old people + 4 children i.e., 7 people got their decks confirmed and to confirm the decks in which the remaining 15 people have to get in is ¹⁵C₇

Now number of ways people can be arranged in lower deck = 10!

Number of ways people can be arranged in upper deck = 12!

Total number of arrangements made with given conditions in a double decker bus = ¹⁵C₇×10!×12!= 11185323474124800000