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A committee of 6 is to be chosen from 10 men and 7 women so as to contain atleast 3 men and 2 women. The number of different ways in which this can be done if two particular women refuse to serve on the same committee

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Important Questions on Permutation and Combination

EASY
The number of ways of selecting 15 teams from 15 men and 15 women, such that each team consists of a man and a woman is
MEDIUM
A debate club consists of 6 girls and 4 boys. A team of 4 members is to be selected from this club including the selection of a captain (from among these 4 members) for the team. If the team has to include at most one boy, then the number of ways of selecting the team is
HARD
Let Tn be the number of all possible triangles formed by joining vertices of an n-sided regular polygon. If Tn+1-Tn=10, then the value of n is :
HARD
The number of noncongruent integer-sided triangles whose sides belong to the set {10, 11, 12,......,22} is
EASY
The value of C916+C1016-C616-C716 is
HARD
If in a regular polygon the number of diagonals is 54, then the number of sides of this polygon is:
EASY
Consider three boxes, each containing 10 balls labelled 1, 2, ., 10. Suppose one ball is randomly drawn from each of the boxes. Denote by ni, the label of the ball drawn from the ith box, i=1, 2, 3. Then, the number of ways in which the balls can be chosen such that n1<n2<n3 is :
EASY
A password is set with 3 distinct letters from the word LOGARITHMS. How many such passwords can be formed?
MEDIUM
The number of selection of n objects from 2n objects of which n are identical and the rest are different, is
MEDIUM
In order to get through in an examination of nine papers, a candidate has to pass in more papers than the number of papers in which he fails. The number of ways in which he can fail, in this examination is
MEDIUM
A man X has 7 friends, 4 of them are ladies and 3 are men. His wife Y also has 7 friends, 3 of them are ladies and 4 are men. Assume X and Y have no common friends. Then the total number of ways in which X and Y together can throw a party inviting 3 ladies and 3 men, so that 3 friends of each of X and Y are in this party is:
EASY
Total number of 6-digit numbers in which only and all the five digits 1,3,5,7 and 9 appears, is
EASY
If Cnr-1=36, Cnr=84 and Cnr+1=126 , then n=
HARD
Let A=x1,x2,,x7 and B=y1,y2,y3 be two sets containing seven and three distinct elements respectively. Then the total number of functions f:AB that are onto, if there exist exactly three elements x in A such that fx=y2, is equal to:
MEDIUM
The number of diagonals of a polygon with 15 sides is
HARD
In a tournament with five teams, each team plays against every other team exactly once. Each game is won by one of the playing teams and the winning team scores one point, while the losing team scores zero. Which of the following is NOT necessarily true?
MEDIUM
The least value of a natural number n such that n-15+n-16<n7, where nr=n!n-r! r! , is
MEDIUM
Let (1+x)n=C0+C1x+C2x2++Cnxn, where Cr=Crn and C0+C1C1+C2Cn-1+Cn=AC1C2Cn, then for n=5, A is equal to
EASY

In how many ways a team of 5 members can be chosen from 8 members?

MEDIUM
From 6 different novels and 3 different dictionaries, 4 novels and 1 dictionary are to be selected and arranged in a row on the shelf so that the dictionary is always in the middle. Then the number of such arrangement is