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
3 points are randomly selected on a sphere,what is the probability that all of them lie in the same hemisphere?
Should it not be?-2πrsq./4πrsq.
An institute has 5 departments and each department has 50 students. If students are picked up randomly from all 5 departments to form a committee, what should be the minimum number of students in the committee so that at least one department should have representation of minimum 5 students?
5. None of the above
In how many ways can we select 3 numbers from first 20 positive integers, such that their product is always divisible by 5?
Sir, won't the answer be 580?
How many 3-letter words can be formed using the letters of the word 'INSTITUTE'?