A person invested Rs. 2,000 on simple interest for 7 years to obtain a total amount of Rs. 3,400 on a certain annual rate of interest. What was the rate of interest to obtain the above amount ?
A can do a piece of work in 20 days while B can do it in 30 days. They work together for 10 days and the rest of the work is done by C in 5 days. If they get Rs 560 for the whole work, how much money will A get?
A and B working alone can complete a work in 8 days and 12 days, respectively. They started working together, but A left 2 days before completion of the work. In how many days was the work completed?