Elitmus Exam

Find the no of ways you can fill a 3x3 grid(with 4 corners defined as a,b,c,d)if you have 3 white marbles and 6 black marbles.
a)9C3 b)6C3 c)9C3+6C3 d)(9C3+6C3)/3!

Read Solution (Total 2)

As here the order of the event matters I think the no of ways should be
9!/(6!x3!)(Permutation with similar items)
=9!/{(9-3)!x3!=9C3
11 years agoHelpfull: Yes(21) No(0)

9C3 or 9C6
11 years agoHelpfull: Yes(4) No(0)

Elitmus Other Question

there are three players playing an chess competetion at a time only 2 players can play the chess game and player A wins 15 games player B wins 14 games and player c wins 9 games ..
so who played the 11 th match and how many games did player C lost . The circle O having a diameter of 2 cm,has a square inscribed in it.Each side of the square is then taken as a diameter to form 4 smaller circles O".Find the total area of all four O" circles which is outside the circle O.
Options:-
1)2
2)pi-2
3)2-pi/4
4)2-pi/2