Find the surface area (in sq.cm) of a sphere of diameter 14 cm.

The area of a circle is 616 sq.cm. Find its radius (in cm).

The perimeter of a square is 26 cm. Find its area (in cm2).

The line graph shows the production of steel of a certain country. Study the diagram and answer the following questions.

If 1 tonne of steel costs Rs 30,000, then what was the cost (in Rs billion) of the steel production in the year 2017?

The line graph shows the production of steel of a certain country. Study the diagram and answer the following questions.

The steel production in 2012 were greater than that in 2015 by ________.

The line graph shows the production of steel of a certain country. Study the diagram and answer the following questions.

What was the difference (in million tonnes) in the steel production between the years 2011 and 2015?

The line graph shows the production of steel of a certain country. Study the diagram and answer the following questions.

In which year was the steel production lesser than that of the previous year?

A boat covers 143 km upstream in 13 hours and the same distance downstream in 11 hours. What is the speed (in km/hr) of the boat in still water?