RS Aggarwal Solutions for Class 7 Maths Exercise 9B Chapter 9 Unitary Method

RS Aggarwal Solutions for the Exercise 9B of Class 7 Maths Chapter 9. In this exercise, students are going to solve the problems on Inverse Variation. Two quantities a and b are said to vary inversely if the product ab remains constant. By practising RS Aggarwal Solutions for Class 7 Maths Chapter 9 Unitary Method, students can gain more knowledge about the topic. Students who wish to score good marks in Maths practise RS Aggarwal Class 7 Solutions Chapter 9. Our expert professors formulate these exercises to support you with your exam preparation and come out with flying colours.

Download the PDF of RS Aggarwal Solutions For Class 7 Maths Chapter 9 Unitary Method – Exercise 9B

 

rs aggarwal solution class 7 maths chapter 9b
rs aggarwal solution class 7 maths chapter 9b

 

Access answers to Maths RS Aggarwal Solutions for Class 7 Chapter 9 – Unitary Method Exercise 9B

1. If 48 men can dig a trench in 14 days, how long will 28 men take to dig a similar trench?

Solution:-

From the question,

48 men can dig a trench in 14 days

1 man can dig a trench in = (14 × 48) days … [less men, more days]

∴ 28 men can dig a similar trench in = (14 × 48)/ 28

= 24 days … [More men, less days]

Hence, the required number of days for 28 men to dig a trench = 24.

2. 16 men can reap a field in 30 days. How many men must be engaged to reap the same field in 24 days?

Solution:-

From the question,

16 men can reap a field in 30 days

1 man can reap a field in = (16 × 30) days … [less men, more days]

∴Number of men required to reap a field in 24 days = (16 × 30) / 24

= 20 men … [More men, less days]

Hence, 20 men required to reap a field in 24 days.

3. 45 cows can graze a field in 13 days. How many cows will graze the same field in 9 days?

Solution:-

45 cows can graze a field in 13 days

1 cow can graze a field in = (45 × 13) days … [less cows, more days]

∴Number of cows required to graze a field in 9 days = (45 × 13)/ 9

= 65 cows … [More cows, less days]

Hence, 65 cows required to graze a field in 9 days.

4. 16 horses can consume a certain quantity of corn in 25 days. In how many days would the same quantity be consumed by 40 horses?

Solution:-

From the question,

16 horses can consume a certain quantity of corn in 25 days

1 horse can consume a certain quantity of corn = (16 × 25)

∴Number of days taken by 40 horses to consume same quantity of corn = (16 × 25) / 40

= 10 days

5. A girl can finish a book in 25 days if she reads 18 pages of it every day. How many days will she take

to finish it, if she reads 15 pages every day?

Solution:-

From the question,

Number of days taken to finish the book if she reads 18 pages every day = 25

Number of days taken to finish the book if she read 1 page every day = (18 × 25)

∴Number of days taken to finish the book if she reads 15 pages every day = (18 × 25)/ 15

= 30 days

6. Reeta types 40 words per minute and takes 24 minute to type a certain document. Her friend Geeta

has a typing speed of 48 words per minute. In how much time, will she be able to type the same

document?

Solution:-

From the question,

Reeta types 40 words per minute in = 24 minutes

Reeta type a word per minute = (24 × 40) minutes

∴Time taken to type 48 words per minute = (24 × 40) / 48

= 20 minutes

Hence, Geeta will take 20 minutes to type the same document, if her typing speed is 48 words per

minute.


Access other exercises of RS Aggarwal Solutions For Class 7 Chapter 9 – Unitary Method

Exercise 9A Solutions

Exercise 9C Solutions