In the given figure, PQRS is square whose side is 8 cm. PQS and QPR are two quadrants. A circle is placed touching both the quadrants and the square as shown in the figure. What is the area ( in cm² ) of the circle ?

An open box is made of wood 3 cm thick. Its external dimensions are 1.36 m, 1.06 m and 8.3 dm. The cost of painting the inner surface of the box at 50 paise per 100 sq. cm (in Rs.) is 

An iron pipe 20 cm long has exterior diameter 25 cm. If the thickness of the pipe is 1 cm, then the whole surface area of the pipe?

A wall is the form of a trapezium with height 8 m and parallel sides being 5 m and 10 m. What is the cost of painting the wall, if the rate of painting is Rs. 50 per square meter  ?

The ratio of the areas of two circles is 16: 25. What will be the ratio of their circumferences?

A field roller, in the shape of a cylinder, has a diameter of 1 meter and length of meter. If the speed at which the roller rolls is 14 revolutions per minute, then the maximum area ( in m²) that it can roll in 1 hour is:

Area of a circle inscribed in a square is 308 cm².The length of the diagonal of the square is

A rectangular ground 16m long and 10m breadth. It has a gravel path 2.5m wide all around it on the outside. What is the area of the path?