Two circles of same radius intersect each other at P and Q. If the length of the common chord is 30 cm and distance between the centres of the two circlesis 40 cm, then what is the radius (in cm) of the circles?
If price of an article decreases from Rs. 25 to Rs. 20, quantity demanded increases from Q1 units to 1500 units. If point elasticity of demand is -1.25, find Q1?