Question

An elevator in a high-rise office building descends at a rate of 30 floors per minute. Which of these gives an equivalent unit rate?

(A) Descending 18 floors in a minute
(B) Descending 36 floors in a minute
(C) Descending 24 floors in 2 minutes
(D) Descending 22.5 floors in 1.5 minutes

Answer 1

Descending 30 floors in a minute is equivalent to descending 1 floor every 2 seconds. The equivalent unit rate is (B) Descending 36 floors in a minute.

Step-by-step explanation:

Descending 30 floors in a minute is equivalent to descending 1 floor every 2 seconds. To find an equivalent unit rate, we need to compare it to the given options:

1. Descending 18 floors in a minute is equivalent to descending 1 floor every 3.33 seconds, which is slower than the original rate.
2. Descending 36 floors in a minute is equivalent to descending 1 floor every 1.67 seconds, which is faster than the original rate.
3. Descending 24 floors in 2 minutes is equivalent to descending 1 floor every 5 seconds, which is slower than the original rate.
4. Descending 22.5 floors in 1.5 minutes is equivalent to descending 1 floor every 4 seconds, which is slower than the original rate.

Therefore, the equivalent unit rate is (B) Descending 36 floors in a minute.