Time and Work Questions

Three electronic devices make a beep after every 48 sec, 72 sec and 108 sec respectively. They beeped together at 10 a.m. The time when they will next make a beep together at the earliest is

Some carpenters promised to do a job in 15 days but 3 of them were absent and remaining did the job in 20 days. What was the original number of carpenters?

Amal is 5 times as good a workman as Bhairav and therefore is able to finish a job in 48 days less than Bhairav. Working together, they can do it in

X is 25% more efficient than Y. If Y alone can make a chair in 10 days, then X alone can make the chair in how many days?

X alone can do a piece of work in 12 days and Y alone can do the same work in 6 days. In how many days will both together complete the same work?

A can do a work in 12 days and B in 24 days. If they work on it together for 4 days, then what fraction of work is left?

Working 7 hours in a day, 4 men can do a piece of work in 8 days. Working 8 hours in a day, the required number of men to perform the same work in 4 days will be

P and Q can complete a task in 50 and 20 days respectively. In how many days can they complete 70% of the task if they work together?