For what value of k, the system of equations kx + 2y = 2 and 3x + y = 1 will be coincident? 

x-y=2, xy=24, then the value of (x²+y²) is:

G is the centroid of ΔABC. The medians AD and BE intersect at right angles. If the lengths of AD and BE are 9 cm and 12 cm respectively; then the length of AB (in cm) is?

In a factory, 60 workers can stitch 120 m of clothes in 7 days, what length of clothes can be stiched by 70 workers in 5 days?

A contractor undertakes to make a road in 40 days and employs 25 men. After 24 days, he finds that only one- third of the road in made. How many extra men should he employ so that he is able to complete the work 4 days earlier?

The no of revolutions a wheel of diameter 40cm makes in travelling a distance of 176m is

The ratio of the length of the parallel sides of a trapezium is 3: 2. The shortest distance between them is 15 cm. If the area of the trapezium is 450 cm.2, the semi-sum of the length of the parallel sides is

The speed of train A is 16 km/h less than the speed of train B. To cover a distance of 384 km, B takes 4 hours less time than A. What is the speed (in km/h) of train B?