Pooja takes 3 times as much as time than Charu and twice as much time as Bano to do a work. If all three work together, she can finish the work in 2 hours. How long will it take Bano to do the whole work alone?
Pipes A, B and C can fill a tank in 15, 30 and 40 hours, respectively. Pipes A, B and C are opened at 6 a.m., 8 a.m. and 10 a.m., respectively, on the same day. When will the tank be full?
An article is sold at a certain price. If it is sold at 80% of this price, then there will be a loss of 10%. What is the percentage profit when the article is sold at the original selling price?