Some workers are painting a hall with length, breadth and height of 15 m, 30 m and 8 m respectively. If they can paint 10 m^{2} area from one liters of paint, find the amount of paint required to paint the walls and ceiling of hall.

The graph below shows the average daily circulation (in thousands) of two newspapers (A and B) for ten years. Find the average daily circulation of B in the year when combined average daily circulation was minimum.

Elizabeth picks a three digit number and subtract it from the same number after reversing order of its digits. This difference will always be fully divisible by which of following number?

In an examination, Sandra attempted 17 questions correctly and secured 57 marks. If there were two types of questions i.e. of 3 marks and 4 marks, how many questions of 3 marks did she attempt correctly?