Mathematics carries the highest weight in AISSEE — 150 of 300 marks in Class 6 and 200 of 400 marks in Class 9 — and it is also a key section of the RMS CET. Practise these 10 MCQs on Time and Work, then check your answers and step-by-step solutions in the answer key at the end.
Quick facts: AISSEE 2027 will be held on Sunday, 31 January 2027. There is no negative marking, so attempt every question. Online applications are open until 2 December 2026 on exams.nta.nic.in/sainik-school-society.
Practice Questions
Q1. A can do a piece of work in 10 days and B can do it in 15 days. In how many days can they finish it working together?
(A) 25 days
(B) 25/2 days
(C) 8 days
(D) 6 days
Q2. A pipe fills a tank in 8 hours and another pipe empties it in 24 hours. If both are opened together, in how many hours will the tank be full?
(A) 6 hours
(B) 12 hours
(C) 16 hours
(D) 15 hours
Q3. Ravi can complete a job in 12 days. What fraction of the job is left after he works for 4 days?
(A) 2/3
(B) 1/3
(C) 3/4
(D) 1/4
Q4. Ravi can complete a job in 15 days. What fraction of the job is left after he works for 5 days?
(A) 1/3
(B) 11/15
(C) 2/3
(D) 1/5
Q5. A can do a piece of work in 18 days and B can do it in 9 days. In how many days can they finish it working together?
(A) 27 days
(B) 27/2 days
(C) 8 days
(D) 6 days
Q6. A pipe fills a tank in 10 hours and another pipe empties it in 15 hours. If both are opened together, in how many hours will the tank be full?
(A) 6 hours
(B) 5 hours
(C) 30 hours
(D) 33 hours
Q7. Ravi can complete a job in 20 days. What fraction of the job is left after he works for 3 days?
(A) 17/20
(B) 3/20
(C) 9/10
(D) 1/3
Q8. A can do a piece of work in 12 days and B can do it in 24 days. In how many days can they finish it working together?
(A) 36 days
(B) 8 days
(C) 18 days
(D) 10 days
Q9. A can do a piece of work in 15 days and B can do it in 10 days. In how many days can they finish it working together?
(A) 6 days
(B) 25 days
(C) 25/2 days
(D) 8 days
Q10. Ravi can complete a job in 15 days. What fraction of the job is left after he works for 4 days?
(A) 4/15
(B) 11/15
(C) 4/5
(D) 1/4
Answer Key with Explanations
(D) 6 days — Together in one day: 1/10 + 1/15 = 1/6; time = 6 days.
(B) 12 hours — Net filling per hour = 1/8 − 1/24 = 1/12; time = 12 hours.
(A) 2/3 — In 4 days he does 4/12; remaining = 1 − 1/3 = 2/3.
(C) 2/3 — In 5 days he does 5/15; remaining = 1 − 1/3 = 2/3.
(D) 6 days — Together in one day: 1/18 + 1/9 = 1/6; time = 6 days.
(C) 30 hours — Net filling per hour = 1/10 − 1/15 = 1/30; time = 30 hours.
(A) 17/20 — In 3 days he does 3/20; remaining = 1 − 3/20 = 17/20.
(B) 8 days — Together in one day: 1/12 + 1/24 = 1/8; time = 8 days.
(A) 6 days — Together in one day: 1/15 + 1/10 = 1/6; time = 6 days.
(B) 11/15 — In 4 days he does 4/15; remaining = 1 − 4/15 = 11/15.
How did you score?
9–10 correct: excellent — move on to a full-length mock test. 6–8: good — revise the explanations of the questions you missed. Below 6: study this topic again from your NCERT book and retry these questions after two days.
Free AISSEE / RMS Mock Test
Want a full-length mock test with an All-India rank? Enunciate Academy runs online coaching for Sainik School, RMS, Navodaya and RIMC entrance exams for Class 6 and 9 students across Andhra Pradesh and Telangana. Message us on WhatsApp (94924 44498) to get a free mock test, or see the Spark batch details.
