How many straight lines can be drawn from 15 non-collinear points?

More Questions from Permutation and Combination

• A library has 'a' copies of one book, 'b' copies of each of two book, 'c' copies of each of three books and single copy of 'd' book. The number of ways in which these books can be distribute is?
• The number of triangles that can be formed by choosing the vertices from a set of 12 points, seven of which lie on the same straight line, is?
• How many words of 4 consonants and 3 vowels can be made from 12 consonants and 4 vowels. If all the letters are different?
• 12 persons are to be arranged to a round table. If two particular persons among them are not to be side by side, the total number of arrangements is?
• The total number of selections of fruit which can be made from 3 bananas, 4 apples and 2 oranges is?
• The total number of arrangements of the letters in the expression a 3b 2c 4 when written at full length is?
• If nC r - 1 = 36, nC r = 84 and nC r + 1 = 126 then?
• If 35C n + 7 = 35C 4n - 2, then all the values of n are given by?
• If 2n + 1P n - 1 : 2n - 1P n = 3 : 5, then n is equal to?
• If nP r= 720 nC r than the value r is?

Discussion & Comments