Home
Class 12
MATHS
There are 12 points in a plane of which ...

There are 12 points in a plane of which 5 are collinear. Except these five points no three are collinear, then

A

The number of quadrilaterals one can form using these points is 420

B

the number of Deltas one can form using these points is 210

C

the number of lines one can form using these points is 57

D

the number of lines one can form using these points is 56

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the number of quadrilaterals, triangles, and lines that can be formed using the given points in the plane, considering that 5 of these points are collinear. ### Step 1: Calculate the number of quadrilaterals A quadrilateral can be formed by selecting 4 points. However, we cannot select all 4 points from the 5 collinear points, as they do not form a quadrilateral. 1. **Total points**: 12 2. **Collinear points**: 5 The number of ways to choose 4 points from 12 is given by \( \binom{12}{4} \). \[ \binom{12}{4} = \frac{12 \times 11 \times 10 \times 9}{4 \times 3 \times 2 \times 1} = 495 \] Now, we need to subtract the cases where all 4 points are chosen from the 5 collinear points: \[ \binom{5}{4} = 5 \] Thus, the number of valid quadrilaterals is: \[ \text{Valid Quadrilaterals} = \binom{12}{4} - \binom{5}{4} = 495 - 5 = 490 \] ### Step 2: Calculate the number of triangles A triangle can be formed by selecting 3 points. We need to subtract the cases where all 3 points are chosen from the 5 collinear points. 1. **Total ways to choose 3 points from 12**: \[ \binom{12}{3} = \frac{12 \times 11 \times 10}{3 \times 2 \times 1} = 220 \] 2. **Subtract the cases where all 3 points are collinear**: \[ \binom{5}{3} = 10 \] Thus, the number of valid triangles is: \[ \text{Valid Triangles} = \binom{12}{3} - \binom{5}{3} = 220 - 10 = 210 \] ### Step 3: Calculate the number of lines A line can be formed by selecting 2 points. We need to subtract the cases where both points are chosen from the 5 collinear points. 1. **Total ways to choose 2 points from 12**: \[ \binom{12}{2} = \frac{12 \times 11}{2 \times 1} = 66 \] 2. **Subtract the cases where both points are collinear**: \[ \binom{5}{2} = 10 \] Thus, the number of valid lines is: \[ \text{Valid Lines} = \binom{12}{2} - \binom{5}{2} = 66 - 10 = 56 \] ### Final Results - Number of valid quadrilaterals: **490** - Number of valid triangles: **210** - Number of valid lines: **56**

To solve the problem, we need to find the number of quadrilaterals, triangles, and lines that can be formed using the given points in the plane, considering that 5 of these points are collinear. ### Step 1: Calculate the number of quadrilaterals A quadrilateral can be formed by selecting 4 points. However, we cannot select all 4 points from the 5 collinear points, as they do not form a quadrilateral. 1. **Total points**: 12 2. **Collinear points**: 5 ...
Promotional Banner

Topper's Solved these Questions

  • TEST PAPERS

    RESONANCE ENGLISH|Exercise PART : 1MATHEMATICS SEC - 1|1 Videos
  • TEST PAPERS

    RESONANCE ENGLISH|Exercise PART : 1MATHEMATICS|9 Videos
  • TEST PAPER

    RESONANCE ENGLISH|Exercise MATHEMATICS|48 Videos
  • TEST SERIES

    RESONANCE ENGLISH|Exercise MATHEMATICS|132 Videos

Similar Questions

Explore conceptually related problems

There are 16 points in a plane of which 6 points are collinear and no other 3 points are collinear.Then the number of quadrilaterals that can be formed by joining these points is

There are 12 points in a plane of which 5 are collinear . Find the number of straight lines obtained by joining these points in pairs .

There 12 points in a plane of which 5 are collinear . Find the number of straight lines obtained by joining these points in pairs.

There 12 points in a plane of which 5 are collinear . Find the number of triangles that can be formed with vertices at these points.

There are 10 points on a plane of which 5 points are collinear. Also, no three of the remaining 5 points are collinear. Then find (i) the number of straight lines joining these points: (ii) the number of triangles, formed by joining these points.

There are 10 points on a plane of which 5 points are collinear. Also, no three of the remaining 5 points are collinear. Then find (i) the number of straight lines joining these points: (ii) the number of triangles, formed by joining these points.

There are 12 points in a plane of which 5 are collinear. The maximum number of distinct quadrilaterals which can be formed with vertices at these points is:

There are 10 points on a plane of which no three points are collinear. If lines are formed joining these points, find the maximum points of intersection of these lines.

There are 10 points on a plane of which no three points are collinear. If lines are formed joining these points, find the maximum points of intersection of these lines.

There are 10 points in a plane out of which 5 are collinear. Find the number of quadrilaterals formed having vertices at these points.

RESONANCE ENGLISH-TEST PAPERS-MATHEMATICS
  1. There are 12 points in a plane of which 5 are collinear. Except these ...

    Text Solution

    |

  2. The least positive vlaue of the parameter 'a' for which there exist at...

    Text Solution

    |

  3. The locus of the midpoint of a chord of the circle x^2+y^2=4 which sub...

    Text Solution

    |

  4. If f(x)=x + tan x and f si the inverse of g, then g'(x) equals

    Text Solution

    |

  5. Tangents PA and PB are drawn to parabola y^(2)=4x from any arbitrary p...

    Text Solution

    |

  6. If lim(nrarroo) (n.2^(n))/(n(3x-4)^(n)+n.2^(n+1)+2^(n))=1/2 where "n" ...

    Text Solution

    |

  7. Eccentricity of ellipse 2(x-y+1)^(2)+3(x+y+2)^(2)=5 is

    Text Solution

    |

  8. If (tan^(-1)x)^(3)+(tan^(-1)y)^(3)=1-3tan^(-1)x.tan^(-1)y. Then which ...

    Text Solution

    |

  9. If f:RrarrR is a continuous function satisfying f(0)=1 and f(2x)-f(x)=...

    Text Solution

    |

  10. tan^(-1)(sinx)=sin^(-1)(tanx) holds true for

    Text Solution

    |

  11. The function f(x) = (x^(2) - 1)|x^(2) - 3x + 3|+cos (|x|) is not diffe...

    Text Solution

    |

  12. Consider parabola P(1)-=y=x^(2) and P(2)-=y^(2)=-8x and the line L-=lx...

    Text Solution

    |

  13. If the normals at (x(i),y(i)) i=1,2,3,4 to the rectangular hyperbola x...

    Text Solution

    |

  14. Let f(x) = x^(3) - x^(2) + x + 1 and g(x) = {{:(max f(t)",", 0 le t le...

    Text Solution

    |

  15. The sum of the roots of the equation tan^(-1)(x+3)-tan^(-1)(x-3)="sin"...

    Text Solution

    |

  16. For an ellipse having major and minor axis along x and y axes respecti...

    Text Solution

    |

  17. If f:[0,1]rarrR is defined as f(x)={(x^(3)(1-x)"sin"1/(x^(2)) 0ltxle1)...

    Text Solution

    |

  18. If f(x)=root (3)(8x^(3)+mx^(2))-nx such that lim(xrarroo)f(x)=1 then

    Text Solution

    |

  19. For the curve y=4x^3-2x^5, find all the points at which the tangents p...

    Text Solution

    |

  20. Minimum value of (sin^(-1)x)^(2)+(cos^(-1)x)^(2) is greater than

    Text Solution

    |

  21. If y + b = m(1)(x + a) and y + b = m(2)(x+a) are two tangents to the p...

    Text Solution

    |