What will be the percentage profit after selling an article at a certain price if there is a loss of 45% when the article is sold at one-third of the previous selling price?

Price registered an increase of 10% on foodgrains and 15% on other items of expenditure. If the ratio of expenditure of an employee on foodgrains and other items be 2 : 5, by how much should his salary be increased in order that he may maintain the same level of consumption as before? (Assume that there is no saving out of his monthly salary of `2590).

Two pipes can separately fill a tank in 20 hrs and 30 hrs respectively. Both the pipes are opened to fill the tank but when the tank is one-third full a leak develops in the tank through which one-third of the water supplied by both the pipes leaks out. What is the total time taken to fill the tank?

A bag contains 8 white and 9 black balls. Balls are drawn one by one. Two balls are draws one by one without replacement. What is the probability that one is white and other is black?