The length of a rectangular floor is 7 metres more than its breadth. If the area of the floor is 260 square metres, what is its breadth?
Answer and explanation
Correct answer: 13 m
Let the breadth be \(x\) metres. Then the length is \(x+7\) metres. Using area, \(x(x+7)=260\), so \(x^2+7x-260=0\). Factoring gives \((x-13)(x+20)=0\), hence \(x=13\) or \(x=-20\). Since a length cannot be negative, the breadth is 13 metres. Exam tip: for a rectangle, always use area = length × breadth.
Frequently asked questions
What is the correct answer to this question?
13 m
Why is this the correct answer?
Let the breadth be \(x\) metres. Then the length is \(x+7\) metres. Using area, \(x(x+7)=260\), so \(x^2+7x-260=0\). Factoring gives \((x-13)(x+20)=0\), hence \(x=13\) or \(x=-20\). Since a length cannot be negative, the breadth is 13 metres. Exam tip: for a rectangle, always use area = length × breadth.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Quadratic Equations. Topic: Word Problems and Applications.
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