Every floor of a 20 storey building is 5 meters high. If a lift moves 2 meters every second. How long will it take to move from the 3rd floor to 15th floor?

So distance of building from one to 15 is = 15 × 5 = 75m

Distance of building from one to two is = 5 × 2 = 10

speed of lift = 2m/sec

distance between 3rd floor to 15th floor = 75–10 = 65m

time = distance/ speed

time = 32.5 seconds it would take the lift 32.5 seconds to move from 3^rd floor to 15^th floor