A man can row at a speed of $$4{1\over 2}$$km/hr in still water. If he takes 2 times as long to row a distance upstream as to row the same distance downstream, then the speed of stream (in km/hr) is : 

Find the area of quadrilateral formed by joining points (4,2), (8,2), (8,14) and (4,10). 

What is single discount equivalent to two successive discounts of 15% and 20%?

Study the following graph and answer the question that follow.
Number of candidates passed form institutes C and E together is approximately what percentage of the total number of candidates appeared from institutes A and G together?

A, B and C invested capital in the ratio of 3 : 4 : 8. At the end of the business term, they received the profit in the ratio of 2 : 3 : 5. What is the ratio of their invested time?

A wall of 100 metres can be built by 7 men or 10 women in 10 days. How many days will 14 men and 20 women take to build a wall of 600 metres 

A bookseller allowed 10 % discount on printed price. He gets 30 % commission from publisher. His profit in percent will be