# NCERT Solutions for Class 10 Maths Chapter 4 Exercise 4.2

NCERT Solutions for Class 10 Maths Chapter 4 Exercise 4.2 (Class 10 Ex. 4.2) Quadratic Equations. CBSE NCERT Solutions can be viewed in Video Format Hindi Medium and English Medium also. Class 10 Maths Exercise 4.2 Sols are given in PDF format to free download which are updated for new academic session 2020-2021. MP board and UP board students are using NCERT Books in session 2020-2021, so they also can use these solutions for their doubt solving. Download UP Board solutions for Class 10 Maths Exercise 4.2 in Hindi Medium. NCERT Solutions 2020-21 and all apps based on these solutions for Class 10 Maths have been updated in the session 2020-21 based on latest CBSE Curriculum 2020-21.

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- 1 Class 10 Maths Exercise 4.2 Solutions
- 1.0.1 What would be the nature of roots of a quadratic equation in discriminant b² – 4ac is greater than zero?
- 1.0.2 What would be the nature of roots of a quadratic equation in discriminant b² – 4ac is less than zero?
- 1.0.3 What would be the nature of roots of a quadratic equation in discriminant b² – 4ac is equal to zero?
- 1.0.4 Do the students of class 10 find the roots, if the roots of quadratic equation is imaginary?

## NCERT Solutions for Class 10 Maths Chapter 4 Exercise 4.2

Class: 10 | Maths (English and Hindi Medium) |

Chapter 4: | Exercise 4.2 |

### 10 Maths Chapter 4 Exercise 4.2 Solutions

UP Board, NCERT CBSE Solutions for Class 10 Maths Chapter 4 Exercise 4.2 Quadratic Equations in English medium is given below. Visit to main page of Class 10 Maths Chapter 4 to get all exercises. Download Class 10 Maths Apps for offline use in Hindi and English. These solutions are very helpful for the students of CBSE as well as UP Board following NCERT Books for the academic session 2020-21 onward. Download (Exercise 4.2) in PDF form or use online given below.

#### Class 10 Maths Chapter 4 Exercise 4.2 Solution in Videos

#### Important Questions with Answers

- Out of a group of swans, 7/2 times the square root of the number are playing on the sea shore of a tank. The two remaining ones are playing in the water. What is the total number of swans? [Answer: 16]
- The sum of ages (in years) of a son and his father is 35 and the product of their ages is 150. Find their present ages. [Answer: 30 years, 5 years]
- A peacock is sitting on the top of a pillar, which is 9 m high. From a point 27 m away from the bottom of the pillar, a snake is coming to its hole at the base of the pillar. Seeing the snake, the peacock pounces on it. If their speeds are equal, at what distance from the hole is the snake caught? [Answer: 12m]
- A man is three times as old as his son and six years ago the product of their ages was 288. Find their present ages. [Answer: 42 years, 14 years]
- ₹9000 were divided equally among a certain number of persons. Had there been 20 more persons, each would have got ₹160 less. Find the original number of persons. [Answer: 25]

##### Questions from Board Papers

- A dealer sells a toy for ₹24 and gains as much percent as the cost price of the toy. Find the cost price of the toy. [Answer: ₹20]
- The time taken by a person to cover 150 km was 2.5 hours more than the time taken in return journey. If he returned at a speed of 10 km/h more than the speed of going, what was the speed per hour in each direction? [Answer: 20 km/h, 30 km/h]
- A shopkeeper buys a number of books for ₹80. If he had bought 4 more books for the same amount, each book would cost ₹1 less. How many books did he buy? [Answer: 16]
- Two pipes running together can fill a cistern in 40/13 minutes. If one pipe takes 3 minutes more than the other to fill it, find the time in which each pipe would fill the cistern? [Answer: 5 minutes, 8 minutes]

###### Questions for Practice

- A person on tour has ₹360 for his daily expenses. If he exceeds his tour programme by 4 days, he must cut down his daily expenses by ₹3 per day. Find the number of days of his tour programme. [Answer: 20]
- A chess board contains 64 equal squares and the area of each square is 6.25 cm². A border round the board is 2 cm wide. Find the length of the side of the chess board. [Answer: 12, 16 cm]

##### What would be the nature of roots of a quadratic equation in discriminant b² – 4ac is greater than zero?

If b² – 4ac > 0, the roots are real and distinct.

##### What would be the nature of roots of a quadratic equation in discriminant b² – 4ac is less than zero?

If b² – 4ac < 0, the roots are imaginary.

##### What would be the nature of roots of a quadratic equation in discriminant b² – 4ac is equal to zero?

If b² – 4ac = 0, the roots are real and equal.

##### Do the students of class 10 find the roots, if the roots of quadratic equation is imaginary?

No, finding the imaginary roots is in class 11 onward. So, in class 10, if roots are imaginary, we should not solve the question any further.