Each of the interior angles of a regular polygon is 140°. How many sides has the polygon?

A cylinder pipe, made of metal is 3cm thick.If the internal radius of the pipe is 10cm.Find the volume of metal used in making 3m of the pipe.

The locus of a point which moves so that it is equidistant from two intersecting straight lines is the?

4, 16, 30, 20, 10, 14 and 26 are represented on a pie chart. Find the sum of the angles of the bisectors representing all numbers equals to or greater than 16

The mean of ten positive numbers is 16. When another number is added, the mean becomes 18. Find the eleventh number