A and B can do a piece of work in 20 days and 12 days respectively. A started the work alone and then after 4 days B joined him till the completion of the work. How long did the work last?

A can do a piece of work in 12 days. When he had worked for 3 days. B joined him. If they complete the work in 3 more days, in how many days can B alone finish the work? 

Raju, Rinku and Ram can do a piece of work in 6, 12, and 24 days respectively. In what time will they finish the work while working together ?

The daily wages of A & B respectively are Rs. 3.5 & Rs. 2.5. When A finishes a certain work alone, he gets a total wages of Rs. 63. When B does the same work alone, he gets a total wages Rs. 75. If both of them do it together what is the cost of the work?

A completes $$ {7\over 10}$$ of work in 15 days, then he completes the remaining work with the help of B in 4 days. The time required for A and B together to complete the entire work is

Vivek is 30% more efficient than Neha. How much time will they, working together, take to complete a job which Vivek alone could have done in 23 days?

A contractor undertakes to make a road in 40 days and employs 25 men. After 24 days, he finds that only one- third of the road in made. How many extra men should he employ so that he is able to complete the work 4 days earlier?

A and B together can complete a particular task in 6 days. If A alone can complete the same task in 10 days, how many days will B take tocomplete the task if he works alone?