A 25m long ladder is rested on a wall. The foot of the ladder is 7m away from the wall. If the end of the ladder (resting on the wall) slides down 4m, then how far will its foot move away?
The weights of 4 boxes are 20, 90, 40 and 60 kilograms. Which of the following cannot be the total weight,in kilograms, of any combination of these boxes and in a combination a box can be used only once?
A helicopter flies 80 km North, then it turns West and flies 50 km, then it turns North and flies 120 km, then it turns to its right and flies 50 km. Where is it now with reference to its starting position?