A can do a piece of work in 18 days and B in 36 days. If they work together for 9 days, then what percentage of work will be left?

The average weight of 8 people is increased by 2 kg when a new person comes in place of the person who weighs 50 kg. What is the weight of the newcomer?

A, B and three men can finish a work in 10, 20 and 15 days respectively, then in how many days will all three together finish the work?

Lal Babu and Mangallu can finish a work in 10 days while Lal Babu alone can finish that work in 15 days, then how many days will Mangallu take to do that work?

In a college 12% of all the students are interested in sports, 10% of the total students are interested in singing and three-fourth of the total students are interested in dancing and remaining 15 students are not interested in any activity, How many total students are there in the college?

Joseph's income is decreased by 10%, by what percent the new income has to be increased to bring his income back to the previous level?

The rate of work of A and B is in the ratio 2 : 3. What will be the ratio of the days taken by them to complete the work?

The number obtained by subtracting two-third of 75% of 600 from a number is 320, what is the original number?