CBSE Class 10-Mathematics: Chapter – 4 Quadratic Equations Part 23 (For CBSE, ICSE, IAS, NET, NRA 2022)

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Question 4:

Is it possible to design a rectangular park of perimeter 80 meters and area 400 m2? If so, find its length and breadth.

Answer:

Let length of park metres

We are given area of rectangular

Therefore, breadth of park metres Perimeter of rectangular park meters We are given perimeter of rectangle metres

According to condition:

Comparing equation, with general quadratic equation

We get

Discriminant Discriminant is equal to 0.

Therefore, two roots of equation are real and equal which means that it is possible to design a rectangular park of perimeter metres and area .

Using quadratic formula to solve equation

Here, both the roots are equal to .

Therefore, length of rectangular park metres

Breadth of rectangular park

Question 5:

If I had walked 1 km per hour faster, I would have taken minutes less to walk . Find the rate of my walking.

Answer:

Distance

Let speed

New speed

Time taken by normal speed

Time taken by new speed

According to question,

So, speed is

Question 6:

A takes 6 days less than the time taken by B to finish a piece of work. If both A and B together can finish it in 4 days, find the time taken by B to finish the work.

Answer:

Let B takes days to finish the work, then A alone can finish it in days.

According to question,

So, B takes days.

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