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TIME AND WORK TYPE 1

Posted on : June 8th 2019, 10:36 pm

TIME AND WORK TYPE 1

This chapter is based on the concept of direct and inverse variations. We need to understand relation among time, work done and number of employees working. In this chapter around 2 to 3 questions asked in various exam Assuming that employee work with the same efficiency, we can conclude that work done is directly proportional to number of employees working and number of days to complete the work is inversely proportional to number of employees working.

Basic Method :

  • For example if a person does a work in 15 days then in 1 day he does only one fifteenth of the work.
  • For example it two men can complete a work working alone in 20 and 30 days respectively, then one day’s work of both the men will be 1/20 and other men work will be 1/30.

Total one day’s work= 1/20+1/30 =5/60=1/12

Total work will be completed by them in days=12 days

LCM METHOD :

  • Then we will take the LCM of numbers and will write at top then we will divide LCM by number invidiously. After that will add those numbers and will divide LCM. We get our answer.

EXAMPLE 2 : If X can do a work in 10 day, Y can do the same work in 20 days, Z can do the work in 30 days. If all 3 started working together, find the total time required to complete the work.