What is the arithmetic mean of 8², 9², 10², …, 15²?

In a class room the ratio of number of girls to that of boys is…

The population of two villages is 1525 and 2600 respectively. If the ratio of male…

A sum was put at simple interest at certain rate for 2 years. Had it…

Students of a class are made to sit in rows of equal number of chairs.…

If 6 men and 8 women can do a piece of work in 10 days;…