Q. 624.3( 10 Votes )

A rectangular field is 16 m long and 10 m wide. There is a path of uniform width all around it, having an area of 120 m2. Find the width of the path.

Answer :

Let the width of the path be x m

Length of the field including the path = 16 + x + x = 16 + 2x


Breadth of the field including the path = 10 + x + x = 10 + 2x


Area of field including the path – Area of field excluding the path = Area of path


(16 + 2x) (10 + 2x) – (16.10) = 120


160 + 32x + 20x + 4x2 – 160 = 120


4x2 + 52x – 120 = 0


x2 + 13x – 30 = 0


Using the splitting middle term – the middle term of the general equation is divided in two such values that:


Product = a.c


For the given equation a = 1 b = 13 c = – 30


= 1. – 30 = – 30


And either of their sum or difference = b


= 13


Thus the two terms are 15 and – 2


Difference = 15 – 2 = 13


Product = 15. – 2 = – 30


x2 + 15x – 2x – 30 = 0


x(x + 15) – 2(x + 15) = 0


(x + 15) (x – 2) = 0


x = 2 or x = – 15


x = 2 (width cannot be negative)


Thus the width of the path is 2 m


Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Get To Know About Quadratic Formula42 mins
Quiz | Knowing the Nature of Roots44 mins
Take a Dip Into Quadratic graphs32 mins
Foundation | Practice Important Questions for Foundation54 mins
Nature of Roots of Quadratic Equations51 mins
Getting Familiar with Nature of Roots of Quadratic Equations51 mins
Quadratic Equation: Previous Year NTSE Questions32 mins
Champ Quiz | Quadratic Equation33 mins
Balance the Chemical Equations49 mins
Understand The Concept of Quadratic Equation45 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses