O is the incentre of ∆ABC and ∠A = 30° then ∠BOC is

A boat goes 15 km in an hour in still water, and takes thrice the time to cover the same distance upstream. The speed of the current (in km / hr) is –

Two cones have their heights in the ratio 1:3 and the radii of their bases in the ratio 3:1. Find the ratio of their volumes?

There is 60% increase in an amount in 6 years at simple interest. What will be the compound interest of Rs. 12,000 after 3 years at the same rate?

In a factory, the production of cycles rose to 48,400 from 40,000 in 2 years. The rate of growth per annum is?

A started the business with the investment of Rs. 36000. B and C joined him with some investments after 3 and 6 months. The profit is divided in the ratio of 2 ∶ 3 ∶ 5 at the end of the year. Find the difference between the investment made by B and C in the business.

The angle of elevation of the top of a tower from a point A on the ground is 30^o. On moving a distance of 20 m towards the foot of the tower to a point B, the angle of elevation increase to 60^o.The height of the tower is-

A boat can row 15 km per hour downstream and 9 km per hour upstream. The speed (in km/hour) of the boat in still water is: