The average of marks of 17 students in an examination was calculated as 71. But it was later found that the mark of one student had been wronglyentered as 65 instead of 56 and another as 24 instead of 50. The correct average is
The milk and water in two vessels are in the ratio of 3 : 1 and 7 : 11 respectively. In what ratio should the liquid in both the vessels be mixed to obtaina new mixture containing half milk and half water?
To travel 708 km, an Express train takes 6 hours more than Rajdhani train. If however, the speed of the Express train is doubled, it takes 3 hours less than Rajdhani train. What is the speed of Rajdhani train?
A wholesaler sells a jacket to a retailer at a profit of 25% and the retailer sells it to a customer at a profit of 20%. If the customer pays Rs. 2,400, what had it cost (in Rs) the wholesaler?