
What would be the sum of nck + nc2k + nc3k + nc4k ...

Q.1 In how many ways can clean & clouded (overcast) days occur in a week assuming that an entire day is either clean or clouded. Q.2 Four visitors A , B , C & D arrive at a town which has 5 hotels . In how many ways can they ...

number of permutations of taken all at a time such that the digit 1,2,3,4,5,6,7,8,9 appearing somewhere to the left of 2. 3 appearing to the left of 4. 5 appearing to the left of 6. eg 815723946 ...

If m men and n women are to be seated in a row such that no two women seat together,then find the ways in this can be done. ...

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There are three coplanar parallel lines.If any p points are taken on each of the line,the maximum number of triangles with vertices at these points is a.3p2(p1) b.3p2(p1)+1 c.p2(4p3) d.None of these ...

If A = {1,2,3,4....18,19} then the number of functions f : Aâ†’A such that f(x)=y and sum of digits of x is equal to the sum of digits of y is (a) 540 (b) 219 (c) 218 (d) 720 ...

Number of zeroes at the end of the number Î rr where r varies from 1 to 25, is (a) 50 (b) 49 (c) 49 (d) 100 ...

A flight of stairs has 10 steps. A person can go up the steps one at a time, two at a time, or any combination of 1's and 2's. Find the total number of ways in which the person can go up the stairs. ...

in how many ways we can make a 4 digit no. using 1,2,3,4 and what's the sum of all the numbers obtained?(repeatations not allowed) ...

Three distinct numbers are selected uniformly at random from the tenterm geometric sequence with first term 10/9 and common ratio 2 . What is the expected value of their sum? ...

\hspace{16}$In how many ways can the selection of $\bf{8}$ letters be done frm $\bf{24}$ letters\\\\ of which $\bf{8}$ are $\bf{'a'}$ and $\bf{8}$ are $\bf{'b'}$ and rest are unlike. ...

Three children,each accompanied by a guardian,seek admission in a school.The principal wants to interview all the 6 persons one after the other,subject to the condition that no child is interviewed before its guardian.In how ...

There are 5 different red balls,5 different green balls,5 different blue balls and 5 different black balls.In how many ways can they be arranged so that no two balls of same color are adjacent ? ...

\hspace{16}\bf{(1)\;\;}$ Total Integer ordered pair,s of $\bf{(x,y)}$ in $\bf{x^2y! = 2001}$\\\\\\ $\bf{(2)\;\;}$ Total Integer ordered pair,s of $\bf{(x,y)}$ in $\bf{x^27y! = 2011}$\\\\\\ $\bf{(3)\;\;}$ Total Integer orde ...