Time & Work
20 Questions
Practice Problems
Time & Work Interview Questions
20 Questions
Time & Work Basics
What is the basic formula of Time and Work?
Time and Work problems are based on the relationship between work done, rate of work, and time taken. Formula: Work = Time × Efficiency Example: If a person completes a job in 10 days, then his one day's work = 1/10.
What is meant by one day's work?
One day's work is the fraction of total work completed in one day. Formula: One Day's Work = 1 / Total Days Required Example: If A completes a work in 20 days, One day's work = 1/20.
A can complete a work in 12 days. What part of work does he complete in one day?
One day's work is found by taking the reciprocal of total days. Formula: One Day's Work = 1/12 Answer: A completes 1/12 of the work in one day.
A completes a work in 10 days and B completes it in 15 days. How much work do they complete together in one day?
Add their individual work rates. Formula: Combined Work = 1/10 + 1/15 = 3/30 + 2/30 = 5/30 = 1/6 Answer: Together they complete 1/6 of the work per day.
A can do a work in 10 days and B in 15 days. In how many days will they complete it together?
First find combined work rate. 1/10 + 1/15 = 1/6 Time = 1 ÷ (1/6) = 6 days Answer: They will complete the work in 6 days.
A can do a work in 8 days. B is twice as efficient as A. In how many days can B do the work?
Time and efficiency are inversely proportional. B's efficiency = 2 × A Time taken by B = 8/2 = 4 days Answer: B can complete the work in 4 days.
If A is 50% more efficient than B, what is the ratio of time taken by A and B?
Efficiency ratio = 150 : 100 = 3 : 2 Time ratio is inverse of efficiency ratio. Time Ratio = 2 : 3 Answer: A and B take time in the ratio 2:3.
A can complete a work in 18 days and B in 9 days. How many days will they take together?
Combined work rate: 1/18 + 1/9 = 1/18 + 2/18 = 3/18 = 1/6 Time = 6 days Answer: Together they finish the work in 6 days.
If 6 men can complete a work in 12 days, how many man-days are required?
Man-days represent total work. Formula: Work = Men × Days = 6 × 12 = 72 man-days Answer: 72 man-days.
If 8 men can do a work in 15 days, how many days will 12 men take?
Men × Days = Constant 8 × 15 = 12 × x 120 = 12x x = 10 Answer: 12 men will take 10 days.
A can complete a work in 20 days. After working for 5 days, what fraction of work remains?
Work done in 5 days = 5 × (1/20) = 1/4 Remaining work = 1 - 1/4 = 3/4 Answer: 3/4 of the work remains.
A can do a work in 24 days and B in 12 days. Find their efficiency ratio.
Efficiency is inversely proportional to time. Efficiency Ratio = 1/24 : 1/12 = 1 : 2 Answer: Efficiency ratio = 1:2.
A and B together complete a work in 8 days. If A alone can do it in 24 days, how many days can B alone take?
Combined rate = 1/8 A's rate = 1/24 B's rate = 1/8 - 1/24 = 3/24 - 1/24 = 2/24 = 1/12 Answer: B alone can complete the work in 12 days.
A can complete a work in 30 days. B can complete the same work in 20 days. What is the ratio of their efficiencies?
Efficiency ratio = 1/30 : 1/20 = 20 : 30 = 2 : 3 Answer: Efficiency ratio = 2:3.
If 12 workers can complete a work in 18 days, how many workers are needed to complete it in 9 days?
Workers × Days = Constant 12 × 18 = x × 9 216 = 9x x = 24 Answer: 24 workers are needed.
A completes 1/15 of a work in a day. How many days will he take to complete the entire work?
Time required is the reciprocal of one day's work. Time = 15 days Answer: A will complete the work in 15 days.
A and B can do a work in 12 days. B and C can do it in 15 days. A and C can do it in 20 days. In how many days can A, B, and C together do it?
AB = 1/12 BC = 1/15 AC = 1/20 Adding: AB + BC + AC = 1/12 + 1/15 + 1/20 = 5/60 + 4/60 + 3/60 = 12/60 = 1/5 Therefore, A+B+C = 1/10 Time = 10 days Answer: They complete the work in 10 days.
A can do a work in 25 days. He works for 10 days. What percentage of work is completed?
Work completed = 10 × (1/25) = 10/25 = 40% Answer: 40% of the work is completed.
If A is three times as efficient as B and B takes 18 days, how many days does A take?
Time is inversely proportional to efficiency. A's time = 18/3 = 6 days Answer: A takes 6 days.
A can complete a work in 16 days and B in 48 days. How many days will they take together?
Combined rate: 1/16 + 1/48 = 3/48 + 1/48 = 4/48 = 1/12 Time = 12 days Answer: Together they complete the work in 12 days.