Time and Work Questions

• Classic Pair-Work Problem A can do a piece of work in 10 days and B can do it in 15 days. If they work together from start to finish, in how many days will they complete the work?
• Finding an Individual's Time from a Trio's Combined Time A can do the work in 24 days, B in 30 days, and together with C they finish in 12 days. How long would C take to complete the work alone?
• Efficiency vs. Time — Inverse Relationship A is thrice as efficient as B, and C is twice as efficient as B. What is the ratio of the number of days taken by A, B, and C respectively when working alone?
• Relative Speeds and Combined Duration A takes only 4/5 as many days as B takes to do the same work. Working together, they finish the job in 20/3 days. What is B’s efficiency (as a percentage of the whole job per day)?
• Comparative Efficiency with Time Difference A is thrice as efficient as B. Together they complete the work in 3 days. If B takes 8 days more than A to do the work alone, how many days does A take alone?
• Pairwise Work Times Given — Find C Alone A and B can do a job in 12 days, B and C in 15 days, and C and A in 20 days. How many days will C alone take to complete the job?
• Three Pairwise Times — Find All Together A and B can finish the work in 8 days, B and C in 12 days, and A and C in 8 days. How many days will A, B, and C together take to finish the work?
• Different Individual Times in a Factory Assignment A, B, and C can do the same assignment in 24, 6, and 12 days respectively. If they all work together from the beginning, in how many days will the assignment be completed?
• Mother–Daughter Team vs. Mother Alone A woman can weave a basket in 6 days. With the help of her daughter, they finish in 4 days. How long would the daughter alone take to weave the basket?
• Three Pairwise Times — Find All Three Together P and Q can complete a job in 6 days, Q and R in 10 days, and P and R in 5 days. If all three work together, how long will they take to finish the job?
• Comparative Efficiency with Time Difference (Hours) Romil is twice as efficient as Sanjay and finishes the work 4 hours sooner than Sanjay. If both work together from the start, in how many hours will they finish the work?
• Wage calculation with overtime: A worker is paid ₹ 5 per hour for regular time and ₹ 8 per hour for overtime. A regular working day has 8 hours and a regular week has 5 working days. Over 4 weeks he earned a total of ₹ 920 and he was present on all regular working days. What is the total number of hours (regular + overtime) that he worked in those 4 weeks?
• Three pipes with filling and emptying: Pipes A and B can fill a tank in 20 h and 30 h respectively, while pipe C can empty a full tank in 40 h. If all three are opened together on an empty tank, in how many hours will the tank become full?
• Team up with different efficiencies: A man, a woman, and a boy can complete a job in 3 days, 4 days, and 12 days respectively when working alone. How many boys must assist one man and one woman so that the job is finished in 1.5 days?
• Leak and inlet together determine capacity: A leak at the bottom of a tank can empty the full tank in 6 h. An inlet pipe can fill water at 4 L per minute. With the tank initially full, the inlet is opened and, due to the leak, the tank becomes empty in 8 h. What is the capacity of the tank (in liters)?
• Pairwise work times for three workers: A and B can complete a job in 12 days, B and C in 15 days, and C and A in 20 days. In how many days will A alone complete the work?
• Different efficiencies, combined time known: Two friends A and B working together finish a job in 26 days. Their efficiencies (work rates) are in the ratio 8 : 5. If B works alone, how many days will he take to complete the job?
• Separating individual time from combined time: A and B together can complete a work in 35 days, while A alone can do it in 60 days. In how many days will B alone complete the same work?
• Find A’s solo time from three pairwise times: A and B can do a job in 72 days, B and C in 120 days, and A and C in 90 days. How many days would A alone take to complete the work?
• Alternating workers by day: Ram finishes a job in 7 days, Rahim in 8 days, and Robert in 6 days. They work one after another in a three-day cycle: Day 1 Ram, Day 2 Rahim, Day 3 Robert, then repeat. Who is working on the last day when the work finishes?