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 chords can be drawn through 21 points on a circle?
Since 21 points lie on the circumference of a circle.
∴ All the 21 points are distinct and no three of them are collinear. Now, we know that one and only one line can be drawn through 2 distinct points.
∴ Numbers of straight lines formed by 21 points by taking 2 at a time
Hence, the number of chords = 210.