RS Aggarwal Class 8 Chapter 13 Solutions (Time And Work)

RS Aggarwal Class 8 Maths Solutions for Chapter 13 ‘Time and Work’ are prepared by the best subject matter experts for your reference. These RS Aggarwal Class 8 Maths Solutions will give you clarity regarding the calculations of work-done and time-taken in doing a job. You will also come across the very popular topic of ‘pipes and cisterns’ in these solutions. There are 2 exercises in the chapter with 36 questions. 

Time and Work is an important part of Quantitative Aptitude. These types of questions are always asked in competitive exams like CAT, JEE, SSC, and bank entrance exams. Hence, it is very important for you to have a thorough understanding of these concepts. The questions related to time and work are quite challenging and one cannot afford even a single calculation mistake. This is why the more you practice the better. 

To make your learning quick, better, and convenient, our subject matter experts have solved all the exercises of Chapter 13 ‘Time and Work’ of RS Aggarwal Class 8 Maths book. These solutions include stepwise explanations and easy to understand language so you would not get confused on how to solve the problems. We have also provided short cuts, tips, and tricks to solve such problems quickly in competitive exams. 

Important Topics for RS Aggarwal Class 8 Maths Solutions Chapter 13: Time and Work

Time and Work 

  • Every work requires a certain time and a certain workforce that is, the number of people who would do the job. 
  • For example, when we say it takes 10 people to paint a house in 5 days. Here, the time taken is 5 days and the number of people involved is 10 and the work done is the painting of the house. 
  • We usually consider work done as a ‘1’ unit. This topic is a continuation of direct and inverse proportion that you would have studied in the previous chapter of RS Aggarwal Class 8 Maths book. 

Work Done

  • If a person Y can do a work in Z days, then in one day Y completes 1Z part of the whole work.
  • Similarly, if Y can complete 1Z part of the whole work in 1 day, then Y would complete the whole work in Z days. 
  • If two people, X and Y can complete a work ‘W’ and ‘Z’ days respectively. Then, together they would be able to do the work in (WZW+Z ) days.  
  • If X is ‘A’ times efficient than ‘Y’ then, X would take (1X )th of the time Y takes to complete a work. 


  • These two concepts are a very important aspect of time and work. 
  • If the amount of work done is constant, then the time of work done is inversely proportional to efficiency. 
  • This means as the time of work done increases, the efficiency of work done decreases, and vice versa. 
  • Efficiency = 1Time

Pipes and Cisterns 

  • Pipes and cisterns is a famous application of the concept of time and work done. You must understand that there are two kinds of pipes that would be given in the questions. 
  • There is an Inlet pipe that lets the water inside a tank or a container. 
  • There is an Outlet pipe that lets the water out of the tank or the container. 
  • If a pipe can fill a tank in ‘A’ hours, then in one hour it will fill ( 1A )th part of the tank. 
  • Similarly, if a pipe can empty a tank in ‘A’ hours, then in one hour it will empty  ( 1A )th part of the tank.

Rate of Filling 

  • This concept is related to pipes and cisterns. The rate of filling of a tank or a container is inversely proportional to the time taken by the pipe to fill the tank. 
  • For example, if a pipe can fill a tank in 20 hours and another pipe can fill the same tank in 10 hours then, the rate of filling of the tank with the first pipe is greater than the rate of filling the tank with the second pipe.

Exercise Discussion for RS Aggarwal Class 8 Maths Solutions Chapter 13: Time and Work

  • RS Aggarwal Solutions for Class 8 Maths Chapter 13 has two exercises. Exercise 13A comprises 19 questions. There are questions related to work done and pipes and cisterns. You must study the formulas given above to solve these questions correctly. 
  • Exercise 13B has 17 questions. They are also based on the same concepts but involve slightly higher-order thinking. This exercise also includes questions related to the efficiency of work done as well. 
  • You must practice these questions carefully as the calculations can be typical. Also, decoding the word-problems given in these questions is also not very easy in the first go. 

Benefits of RS Aggarwal Class 8 Maths Solutions Chapter 13: Time and Work by Instasolv

  • Practising the exercises of RS Aggarwal Class 8 Maths Chapter 13 ‘Time and Work’ can be very useful for ensuring a solid understanding of the concepts for competitive exams and olympiads. 
  • All the solutions are provided exercise-wise so accessing them is super easy for you. 
  • You can refer to these solutions any time you want and get your doubts cleared on your own. 
  • You can now take your first step to independent learning with the help of these solutions and prepare yourself for all kinds of maths exams in Class 8.