Everybody in a room shakes hands with everybody else. The total number of hand-shakes is 55. The total number of persons in the room is:

The average marks of a student in four subjects is 75. If the student obtained 80 marks in the 5^th subject then the new average is ?

In the given figure AD ‖ BC, if ∠ABC=72°, then ∠BCD=?

How many positive integers less than 1000 are multiples of 11 whose square roots are whole numbers

A milkman has 75 litres milk in one cane and 45 litres in another. The maximum capacity of container which can measure milk of either container exact number: 

A tank of 30 meter long, 20metre wide and 12 meter deep is dug in a rectangular field of length 588 meter and breadth 50 meter. The earth sand so dug out is spread evenly on the remaining part of the field. The height of the field raised by it is

The cost price of an article is Rs. 800. After allowing a discount of 10 %, a gain of 12.5 % is made. Then the marked price of the article is 

The distance between the coordinates ( x,y)  from the original point will be