Determine the number of 5-card combinations out of a deck of 52 cards if each selection of 5 cards has exactly one king.
What is the number of ways of choosing 4 cards from a pack of 52 cards? In how many of these :
(i) four cards are of the same suit?
(ii) four cards belongs to different suit?
(iii) are face cards?
(iv) two are red cards and two are black cards?
(v) cards are of the same colour?
How many straight lines can be formed with 7 points, 3 of which are colinear.
Total number of points = 7.
Number of straight lines formed by these 7 points (no three of which are collinear) by taking 2 at a time
=
It is a given that three points are collinear. If these three points are considered to be distinct, number of straight lines formed by these 3 points by taking 2 at a time =
Instead of these three lines, the 3 collinear points will give us only 1 line.
∴ Required number of straight lines =
Hence, the number of straight lines formed with 7 points, 3 of which are collinear = 19