The angle of elevation of the top of a tower from a point A on the ground is 30°. On moving a distance of 20 metres towards the foot of the tower to a point B, the angle of elevation increases to 60°. The height of the tower is
Two pipes can fill a tank in 10 and 14 minutes respectively. A third pipe can empty the tank at the rate of10 liters/minute. If all the pipes working together can fill the empty tank in 8 minutes, what is the capacity of the tank?
A sold an article to B at 10% loss, B sold it to C at 15% profit and C sold it to D at 10% profit. If D bought it for ₹4,554, then what was the cost price (in ₹) of A?