the elevators in a tall building can pass 84 floors in 42 seconds. At that speed, how many floors can the elevators pass in 24 seconds

48 floors

Step-by-step explanation:

84 floors in 42 seconds

So, how many floors in 1 second? We divide number of floors by number of seconds:

84/42 = 2 floors per second

Now, we want to know how many floors would it cover in 24 seconds

It's simple!

2 floor per second

So, 2 * 24 = 48 floors in 24 seconds

So, it will cover 48 floors (at that speed)