Question

David gets on the elevator at the 11th floor of a building and rides up at the rate of 57 floors per min. At the same time, albert, gets on the elevator at the 51th floor of the same building and rides down at the rate of 63 floors per min. If they continue travelling at these rates, then at which floor will their paths cross?

Answer 1

answer:30

Explanation:

let they meet at xth floor after time 't'.....

so in time t David travells (x-11)floors thus t=(x-11)/57

now in time t albert travells (51-x) floors

thus here t=(51-x)/63

then, (x-11)/57=(51-x)/63........solve for 'x'