From point P, at 6 : 30 pm, a train starts moving towards Q with the speed of 40 km/hr. Another train starts moving from point Q at 7:30 p.m. towards point P at the speed of 60 km/hr. Both of them meet at 11:30 p.m. at point R. What is the ratio of PR and QR?
PQ and RS are common tangents to two circles intersecting at A and B. AB, when produced both sides, meet the tangents PQ and RS at X and Y, respectively. If AB = 3 cm, XY = 5 cm, then PQ (in cm) will be
ABCD is a trapezium in which AB is parallel to CD and AB = 4(CD). The diagonals of the trapezium intersects at O. What is the ratio of area of triangle DCO to the area of the triangle ABO?
A spherical glass vessel has a cylindrical neck 7 cm long and 4 cm in diameter. The diameter of the spherical part is 21 cm. Find the quantity of water it can hold.