AB is a line segment of length 2a,with M as midpoint.Semicircles are drawn on one side with AM,MB and AB as diameter as shown in the above figure.A circle with centre O and radius r is drawn such that this circle touches all the three semi-circles.The value of r is

A river 2.5m deep and 45 m wide is flowing at the speed of  3.6km/hr.The amount of water that runs into the sea per minute is

How many spherical bullets each of 4cm in diameter can be made out of a cube of lead whose edge is 44cm?

The area of a trapezium is 336cm².If its parallel sides are in the ratio 5:7 and the perpendicular distance between them is 14cm,then the smaller of the parallel sides are

If the surface area of a cube is 13254cm²,length of the diagonal is

Three rectangles R1,R2 and R3 have the same area.Their lengths x1,x2 and x3 respectively are such that x1<x2<x3.If V1,V2,V3 are the volumes of the cylinders formed from rectangles R1,R2,R3 respectively by joinng parallel sides along the breadth,then which one of the following is correct?