Time & Work Questions with Solutions

Time and work questions deal with how long one or more people, machines or pipes take to complete a task. The core idea is that if someone finishes a job in n days, they complete 1/n of the job each day. Questions involve people working together, joining or leaving partway, working on alternate days, efficiency comparisons, and wages shared in proportion to work done. Pipes and cisterns questions use the same logic and have their own page. The LCM method is the fastest approach for most questions. Take the total work as the LCM of the individual times, find each person's work per day, and the rest becomes simple division. This avoids messy fractions and makes problems with three or more workers much easier to handle. Practise the time and work questions below. Each solution shows the step-by-step working and the LCM shortcut where it helps.