Use the star and bars method to find the number of integral solutions to the equation
Where x\ge 0, y\ge 1, z\ge 1 ,w\ge 0
Or you can just count cases, although it's a longer method.
(10 for all 3 sitting together)
(90 for 2 sitting together and the third not immediately adjacent to them)
Of course, if the number of people is bigger, you should do what @Rohan_Shinde1 said
How is this equation formed?
Let x be no. of people in the row before the first one to be selected, y be the number of people between the first and second person to be selected and so on
Thanks a lot!
Couldn't get it..can u please explain once ?