Question

an elevator descends into a mine shaft at the rate of 7m/min. If the descent starts from 15 m above the ground level, how long will it take to reach 475 m?

Answer 1

the total height for the mineshaft to cover is 475+15= 490 m
for covering the distance the mineshaft requires=(490/7 )min
=70 min
= 1hr 10 min

Answer 2

Concept:

Rate is the speed at which something happens or the number of times something happens.

Given:

Elevator descends at the rate = 7m/min

And,

The descent starts from 15 m above the ground level.

Find:

We are asked to find the time it will take to reach 475 m.

Solution:

We have,

Elevator descends at the rate = 7m/min

And,

The descent starts from 15 m above the ground level.

So,

The total distance = 15 + 475 = 490m

So,

The time it will take = 490/7 = 70 minutes or 1 hour and 10 minutes

Hence, the time it will take to reach 475 m will be 70 minutes or 1 hour and 10 minutes.

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