Passengers are to travel by a double decked bus which can accommodate 13 in the upper deck and 7 in the lower deck. Find the number of ways that they can be distributed if 5 refuse to sit in the upper deck and 8 refuse to sit in the lower deck.

A double-decker bus carry (u+e) passengers, u in the upper deck and e in the lower deck. Find the number of ways in which the u+e passengers can be distributed in the two decks, if r(lt=e) particular passengers refuse to go in the upper deck and s(lt=u) refuse to sit in the lower deck.

A double-decker bus carry (u+l) passengers, u in the upper deck and l in the lower deck. Find the number of ways in which the u+l passengers can be distributed in the two decks, if r(lt=l) particular passengers refuse to go in the upper deck and s(lt=u) refuse to sit in the lower deck.

Find the number of ways in which 8 distinct toys can be distributed among 5 children.

Find the number of ways in which 8 distinct toys can be distributed among 5 children.

The number of ways in which 5 distinct toys can be distributed among 8 children is

Find the number of ways in which one can post 5 letters in 7letter boxes.

Find the number of ways in which 5 distinct balls can be distributed in three different boxes if no box remains empty.

5 boys & 4 girls sit in a straight line. Find the number of ways in which they can be seated if 2 girls aretogether & the other 2 are also together but separate from the first 2.:

From 6 boys and 7 girls a committee of 5 is to be formed so as to include at least one girl. Find the number of ways in which this can be done.

Find the number of ways in which 6 boys and 6 girls can be seated in a row so that all the girls sit together and all the boys sit together.