Question

Alex gets on the elevator at the 3rd floor of a building and rides up at the rate of 16 floors per minute. At the same time, Bob gets on an elevator at the 60th floor of the same building and rides down at the rate of 22 floors per minute. If they continue travelling at these rates, then at which floor will their paths cross ?

Answer 1

They will cross floor from bottom of building is =27 floor

and from top of building is 33 floor

Step-by-step explanation:

Given,

Actual height of building = $H=60$floor

Alex start moving from 3rd floor

Travelling floor=60-3=57 floor

Speed of Alex=$A=16floor/minute$

Speed of Bob=$B=22floor/minute$

Let time for travelling be $t$ minutes

Solution,

$16\times t+22\times t=57$floor

$38t=57$

$t=57/38$

$t=1.5minutes$

They will cross at this floor from the bottom  $=(16\times 1.5+3)floor$

$=24+3$

$=27floor$

They will cross floor from top of building is     $=22\times 1.5floor$

$=33floor$