Permutation and combination
1. Number of selections of atleast 10 articles from 19 different articles is.
A) 2^19 B) 2^18 C) 2^19 - 1 D) 2^18 - 1 E) None
How many 4-digit numbers can be formed which are divisible by 4 , using the first 8 whole numbers , if repetition of digits is not allowed?
In how many different ways 8 different balls can be placed into 3 identical boxes if (a) blank box is not permitted, (b) blank box is permitted?
A,S, and P go to a seaside town and they decide to visit different tourist locations. After breakfast each of them boards a different tourist vehicle from the nearest bus stop. After 3 hours, S , who had gone to a beach , calls on the mobile of P and claims that he has observed a shark in the waters. P learns from the local guide that at that time of the year , only 8 sea creatures(including shark) are observable and the probability of observing any creature is equal. However , A and P later recall during their discussion that S has a reputation for not telling the truth 5 out of 6 times. What is the probability that S actually observed a shark in the waters?
Find the number of ways in which 14 identical balls can be divided into 3 groups?
In how many ways can 5 identical balls be placed in 5 identical boxes such that there can be any number of balls in any of the box
The number of ways of distributing 20 fruits among 5 people, so that no one receives less than 3 fruits is : __
How many different paths are there on a regular 8 × 8 chessboard from the lower left corner to the upper right corner? The path is always going along the edges of the unit squares to the right, up or down but not left. Also no passage should be retraced on a path.
In how many ways two red balls, one green ball and one blue ball can be put in three boxes of different sizes if order of putting the balls doesn’t matter?
54 or 81?