Speed of boat in still water is 9 km/hr. Stream speed initially is 2 km/hr but it increases by 3 km/hr after every hour. Find the time after which boat will come back to the position where it started.(in hour)

A secant PAB is drawn from an external point P to the circle with centre O, intersecting it at A and B. If OP = 17 cm, PA = 12 cm and PB = 22.5 cm, then the radius of the circle is:

$$ \sqrt{749}×0.56+14.38=?$$

A polygon has 14 sides then find out No. of diagonals in that polygon. 

Chandu bought a watch at 20 percent discount on mark price but sold it at mark price. Find the percentage of profit.

If 20 taps can fill a tank in 14 hours, then how many times will 35 taps fill that tank?

Study the following graph carefully to answer the given questions

The efficiency of L is 25% more than P. L started a work alone and then P joined her 5 days before actual completion of the work. For how many days L worked alone?

In ∆ABC, ∠B is a right angle, AC = 6cm, and D is the mid-point of AC. The length of BD is: