Permutations and Combinations questions
785 published questions with worked solutions.
- If ^nP_r=3024 and ^nC_r=126, then r is
- The letters of the word COCHIN are permuted and all the permutations are arranged in an alphabetical order as in an English...
- If a man and his wife enter in a bus, in which five seats are vacant, then the number of different ways they can be seated, is
- All possible two factors products are formed from numbers 1,2,3,4, ,200. The number of factors out of the total obtained which...
- The number of positive odd divisors of 216 is
- 7 relatives of a man comprise 4 ladies and 3 gentlemen his wife has also 7 relatives; 3 of them are ladies and 4 gentlemen. In...
- If 1 ^4C_n = 1 ^5C_n + 1 ^6C_n , then n is equal to
- The number of permutations of 4 letters that can be made out of the letters of the word EXAMINATION is
- A three digit number n is such that the last two digits of it are equal and differ from the first. The number of such n's is
- S_1,S_2, ,S_ 10 are the speakers in a conference. If S_1 addresses only after S_2, then the number of ways the speakers address is
- There are two urns. Urn A has 3 distinct red balls and urn B has 9 distinct blue balls. From each urn two balls are taken out at...
- Everybody in a room shakes hands with everybody else. The total number of hand shakes is 66. The total number of persons in the...
- Number of divisors of the form (4n+2), n 0 of the integer 240 is
- If ^nP_r=30240 and ^nC_r=252, then the ordered pair (n,r) is equal to
- At an electron, a voter may vote for any number of candidates not greater than the number to be elected. There are 10 candidates...
- The number of ways in which 9 persons can be divided into three equal groups is
- Out of 8 given points, 3 are collinear. How many different straight lines can be drawn by joining any two points from those 8...
- There is a set of m parallel lines intersecting a set of another n parallel lines in a plane. The number of parallelograms...
- Let l_1 and l_2 be two lines intersecting at P. If A_1,B_1,C_1 are points on l_1 and A_2,B_2,C_2,D_2,E_2 are points on l_2 and if...
- The number of words which can be formed the letters of the word MAXIMUM, if two consonants cannot occur together, is
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