Home
Class 8
MATHS
In a school hall, 460 students were sitt...

In a school hall, 460 students were sitting in rows and columns in such a way that the number of students sitting in each column was three more than the number of students sitting in each row.The number of students in each column was:

A

0

B

23

C

24

D

None of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to set up equations based on the information given. Let's denote: - Let \( r \) be the number of students sitting in each row. - Let \( c \) be the number of students sitting in each column. According to the problem, we have two key pieces of information: 1. The total number of students is 460. 2. The number of students in each column is 3 more than the number of students in each row. From this information, we can set up the following equations: 1. The total number of students can be expressed as: \[ r \times c = 460 \] 2. The relationship between the number of students in rows and columns is: \[ c = r + 3 \] Now, we can substitute the second equation into the first equation. ### Step 1: Substitute \( c \) in the total students equation Substituting \( c \) in the equation \( r \times c = 460 \): \[ r \times (r + 3) = 460 \] ### Step 2: Expand the equation Expanding the equation gives us: \[ r^2 + 3r = 460 \] ### Step 3: Rearrange the equation Rearranging the equation to set it to zero: \[ r^2 + 3r - 460 = 0 \] ### Step 4: Solve the quadratic equation Now, we can solve this quadratic equation using the quadratic formula: \[ r = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \( a = 1 \), \( b = 3 \), and \( c = -460 \). Calculating the discriminant: \[ b^2 - 4ac = 3^2 - 4 \times 1 \times (-460) = 9 + 1840 = 1849 \] Now, applying the quadratic formula: \[ r = \frac{-3 \pm \sqrt{1849}}{2 \times 1} \] Calculating \( \sqrt{1849} = 43 \): \[ r = \frac{-3 \pm 43}{2} \] Calculating the two possible values for \( r \): 1. \( r = \frac{40}{2} = 20 \) 2. \( r = \frac{-46}{2} = -23 \) (not a valid solution since the number of students cannot be negative) Thus, \( r = 20 \). ### Step 5: Find \( c \) Now, substituting \( r \) back into the equation for \( c \): \[ c = r + 3 = 20 + 3 = 23 \] ### Conclusion The number of students in each column is \( \boxed{23} \).
Promotional Banner

Topper's Solved these Questions

  • QUADRATIC EQUATIONS

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESSMENT SHEET|10 Videos
  • QUADRATIC EQUATIONS

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESSMENT SHEET|10 Videos
  • PROBABILITY

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESSMENT SHEET -29 |10 Videos
  • RATIO AND PROPORTION

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESEMENT SHEET - 15|10 Videos

Similar Questions

Explore conceptually related problems

8649 students were sitting in a lecture room in such a manner that there were as many students in the row as there were rows in the lecture room. How many students were there in each row of the lecture room?

In a row of students, Sohan is 9th from either end of the row. Find the number of students in a row.

There are some students in the two examination halls A and B. To make the number of students equal in each hall, 10 students are sent from A to B but, if 20 students are sent from B to A, the number of students in A becomes double the number of students in B, then find the number of students in the both halls.

Ina class of 72 children are seated in rows and columns is such a way that the number of children in each row is 12.5% more than the number of children in each column.How many children are there in each row? 8 b.9 c.12 d.18 e.none of these

Direction: There are 1250 total students in 5 different classes in a school. The number of students in class I is 50 less than the number of students in class II. The number of class IV students is 50 more than the number of students in class II. The average number of students in class III and class V is 250. The number of students in class III is 10% less than the number of students in class I. The number of students of class V is what percent of the total number of students?

Direction: There are 1250 total students in 5 different classes in a school. The number of students in class I is 50 less than the number of students in class II. The number of class IV students is 50 more than the number of students in class II. The average number of students in class III and class V is 250. The number of students in class III is 10% less than the number of students in class I. The total number of students of class IV and the number of students of class II is

Direction: There are 1250 total students in 5 different classes in a school. The number of students in class I is 50 less than the number of students in class II. The number of class IV students is 50 more than the number of students in class II. The average number of students in class III and class V is 250. The number of students in class III is 10% less than the number of students in class I. The ratio of the total number of students of class V to the total number of students of class III is

Direction: There are 1250 total students in 5 different classes in a school. The number of students in class I is 50 less than the number of students in class II. The number of class IV students is 50 more than the number of students in class II. The average number of students in class III and class V is 250. The number of students in class III is 10% less than the number of students in class I. The number of students of class I is -

S CHAND IIT JEE FOUNDATION-QUADRATIC EQUATIONS-QUESTION BANK
  1. The values of x satisfying the equation 5^(2x)-5^(x+3)+125=5^(x) are

    Text Solution

    |

  2. The root of the equation 3^(2x)-10.3^(x)+9=0 are

    Text Solution

    |

  3. If one root of the quadratic equaion 3x^(2)-10x+p=0 is 1/3, then the v...

    Text Solution

    |

  4. Thrice the square of a natural number decreased by 4 times the numb...

    Text Solution

    |

  5. The product of two successive natural numbers is 1980. Which is the sm...

    Text Solution

    |

  6. A two digit number is such that the product of digit is 8 . when 18 is...

    Text Solution

    |

  7. The difference of mother's age and her daughter's age is 21 years and ...

    Text Solution

    |

  8. The sum of a number and its positive square root is 6/25.Find the numb...

    Text Solution

    |

  9. In a school hall, 460 students were sitting in rows and columns in suc...

    Text Solution

    |

  10. The length of a hypotenuse of a right triangle exceeds the length of i...

    Text Solution

    |

  11. If the price of an article is increased by Rs. 2 per dozen that at pre...

    Text Solution

    |

  12. If the perimeter of a rectangular plot is 34 metres and its area is 60...

    Text Solution

    |

  13. Two little bands of monkeys were at play. An eighth of them squared we...

    Text Solution

    |

  14. One-fourth of a herd of cows is in the forest. Twice the square root o...

    Text Solution

    |

  15. A positive number when decreased by 4 is equal to 21 times the reci...

    Text Solution

    |

  16. A man in 1900s realised that in the year 1980 his age was the square r...

    Text Solution

    |

  17. A swimming pool is to be built in the shape of the letter L . The shap...

    Text Solution

    |

  18. The speed of a boat in still water is 15 km/hr. It can go 30 km ups...

    Text Solution

    |

  19. The diagonal of a rectangular field is 15 metres and the difference...

    Text Solution

    |

  20. In the following question two equations numbered I and II are given. Y...

    Text Solution

    |