TestUstad
Moderate

A and B working separately can do a piece of work in 9 and 12 days respectively. If they work for a day alternately. If A begins first, in how many days the work will be completed ?

Correct answer: B. 41/4 days

  • A. 42/4 days
  • B. 41/4 days
  • C. 55 days
  • D. None of these

Explanation

In each two-day cycle, A and B complete 1/9 + 1/12 = 7/36 of the work. After four cycles, 28/36 = 7/9 is complete; A then works on day 9, B on day 10, and the remaining 1/36 is completed by A in (1/36) ÷ (1/9) = 1/4 day, giving 10 1/4 = 41/4 days. The likely mistake is 42/4 days, caused by rounding the final quarter-day or mishandling the alternating sequence.

Last updated

About Time and Work

Problems measure work through rates, treating each person's or machine's contribution as work completed per unit time. Questions cover combined work, efficiency, wages, alternate working schedules, pipes and cisterns, and men-days relationships, with care needed to distinguish time taken by one worker from the time required when workers act together.

Practise Arithmetic

1,060 free Arithmetic MCQs from Mathematics, each with the correct answer and an explanation. Unlimited attempts, no account needed.

Start a free Arithmetic testAll Arithmetic MCQs

Exams that ask Mathematics questions like this

Mathematics is on 67 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.

NET Mathematics80 MCQsATS Mathematics30 MCQsCTS Mathematics30 MCQsECAT Mathematics30 MCQsETEA Engineering Admission Test Mathematics30 MCQsETEA Recruitment Tests Mathematics30 MCQsGAT General Mathematics30 MCQsGIKI Mathematics30 MCQsNAT Mathematics30 MCQsNED Mathematics30 MCQsNTS Mathematics30 MCQsOTS Mathematics30 MCQsPIEAS Mathematics30 MCQsPTS Mathematics30 MCQsSTS Mathematics30 MCQsUTS Mathematics30 MCQsBCAT Mathematics25 MCQsISSB Mathematics25 MCQsPAF Mathematics20 MCQsPakistan Army Commissioned Officer Test Mathematics20 MCQsPakistan Navy Test Mathematics20 MCQsPatwari Test Mathematics20 MCQsPMA Long Course Test Mathematics20 MCQsPMD Mathematics20 MCQsComputer Operator Test Mathematics15 MCQsDEO Mathematics15 MCQsEducators ESE Test Mathematics15 MCQsEducators SESE Test Mathematics15 MCQsEducators SST Test Mathematics15 MCQsFBR Mathematics15 MCQsJEST Mathematics15 MCQsJunior Clerk Test Mathematics15 MCQsLAT Mathematics15 MCQsNADRA Mathematics15 MCQsPST Mathematics15 MCQsSub Registrar Test Mathematics15 MCQsAJKPSC Mathematics10 MCQsAssistant BS-16 Test Mathematics10 MCQsBPSC Mathematics10 MCQsECP Mathematics10 MCQsFIA Mathematics10 MCQsFPSC Mathematics10 MCQsGBPSC Mathematics10 MCQsIB Mathematics10 MCQsKPPSC Mathematics10 MCQsMES Mathematics10 MCQsNAB Mathematics10 MCQsNational Highways and Motorway Police Test Mathematics10 MCQsPakistan Railways Recruitment Test Mathematics10 MCQsPCS Mathematics10 MCQsPIA Mathematics10 MCQsPPSC Mathematics10 MCQsPunjab Police ASI Test Mathematics10 MCQsPunjab Police Sub Inspector Test Mathematics10 MCQsSNGPL Mathematics10 MCQsSPSC Mathematics10 MCQsTehsildar and Naib Tehsildar Test Mathematics10 MCQsWAPDA Mathematics10 MCQsANF Mathematics5 MCQsASF Mathematics5 MCQsCTD Mathematics5 MCQsElite Police Force Test Mathematics5 MCQsPakistan Army Soldier Test Mathematics5 MCQsPakistan Rangers Test Mathematics5 MCQsPERA Force Test Mathematics5 MCQsPunjab Police Constable Test Mathematics5 MCQsRescue 1122 Test Mathematics5 MCQs

Related questions

15 men can build a 500m long wall in 30 days. In how many days can 30 men build a 1.2 km long wall?

2 men and 12 women can finish a job in 4 days. 4 men and 6 women can do the same job in 5 days. Find the time taken by 1 man and 1 woman to complete the job.

3 men and 7 women can complete a work in 10 days . But 4 men and 6 women need 8 days to complete the same work . In how many days will 10 women complete the same work?

4 men and 2 woman can complete a work in 2 days. If 2 men alone take 5 days to complete the work, find the time taken by 2 women alone to complete the work.

6 men and 8 women can complete a work in 10 days. 26 men and 48 women can finish the same work in 2 days. 15 men and 20 women can do the same work in_______days.