Advertisements
Advertisements
प्रश्न
How many chords can be drawn through 21 points on a circle?
Advertisements
उत्तर
To draw a chord we need two points on a circle.
∴ Number chords through 21 points on a circle = 21C2 = `(21xx20)/(2xx1) = 210`
APPEARS IN
संबंधित प्रश्न
How many triangles can be formed by joining the vertices of a hexagon?
A committee of 5 is to be formed out of 6 gents and 4 ladies. In how many ways this can be done when
- atleast two ladies are included.
- atmost two ladies are included.
Let there be 3 red, 2 yellow and 2 green signal flags. How many different signals are possible if we wish to make signals by arranging all of them vertically on a staff?
If nC12 = nC9 find 21Cn
How many chords can be drawn through 20 points on a circle?
A box contains two white balls, three black balls and four red balls. In how many ways can three balls be drawn from the box, if at least one black ball is to be included in the draw?
A polygon has 90 diagonals. Find the number of its sides?
Choose the correct alternative:
The number of ways in which a host lady invite 8 people for a party of 8 out of 12 people of whom two do not want to attend the party together is
Choose the correct alternative:
The number of parallelograms that can be formed from a set of four parallel lines intersecting another set of three parallel lines
Choose the correct alternative:
The number of rectangles that a chessboard has ______
