Two trains are moving in the same direction at the speed of 23 km/hr and 77 km/hr. The time taken by faster train to cross a man sitting in the slower train is 40 seconds. What will be the length (in metres) of the faster train?
A certain sum of money becomes double of itself in 15 years at a rate of simple interest. In how many years will it become 5 times of itself at the same rate of simple interest
ABC is an equilateral triangle of side 6 cm. If a circle of radius 1 cm is moving inside and along the sides of the triangle, then the locus of the centre of the circle is an equilateral triangle of side is
The value of a machine depreciates at the rate of 20% per annum. If its present value is Rs 96000, then what was the value (in Rs) of the machine 2 years ago?