A piece of metal is 3 in (in=inch) in length. Express the length in cm unit.

Find the area of a square of length 7 cm.

The perimeter of a rectangle is 200 cm. If its length is three times of its breadth, find the length and breadth of the rectangle.

A compound microscope has an objective of focal length 1 cm, an eye piece of focal length 2.5 cm and a tube of length 15 cm. Find its magnification for normal adjustment.

The centre of a circle is the point (3, 2) and it makes an intercept of length 5 units on the X-axis. Find the equation of the circle.

Form the pair of linear equations in the following problems and find their solutions (if they exist) by any algebraic method:The area of rectangle gets reduced by 9 square units,if its length is reduced by 5 units and breadth is increased by 3 units.If we increase the length by 3 units and the breadth by 2 units,the ares increases by 67 square units.Find the dimensions of the rectangle.

Two ropes are of length 64 cm and 80 cm. Both are to be cut into pieces of equal length. What should be the maximum length of the pieces?