Question Video: Estimating the Suitable Time for a Given Action | Nagwa Question Video: Estimating the Suitable Time for a Given Action | Nagwa

# Question Video: Estimating the Suitable Time for a Given Action Mathematics

Which of the following would be the best estimate for the amount of time it would take to climb a flight of stairs? [A] 30 minutes [B] 30 seconds [C] 30 hours

02:37

### Video Transcript

Which of the following would be the best estimate for the amount of time it would take to climb a flight of stairs? 30 minutes, 30 seconds, or 30 hours?

Before we start to think about answering this question, what do you notice about the possible answers that we’re given? Can you see each of these measurements of time contains the same number, 30? But the unit of measurement, that’s a thing we’re measuring time in, is different each time. So this question is really about whether you know what a minute, a second, and an hour is.

Now, our question’s all about the amount of time it takes to climb a flight of stairs. Maybe you live in a house that has stairs in it. At the end of the night, when it’s time to go to bed, how long does it take you to get from the bottom of the stairs to the top? There’s an interesting word in this question, and it’s the word “estimate.” An estimate is a thoughtful guess. In other words, we don’t need to know the exact amount of time it takes you to walk up a flight of stairs. But what we want is a good guess, a guess that we’ve thought carefully about so that it makes sense.

Do any of these amounts of time not make sense? We know that an hour is about the length of time that you have for your lunch time every day. So do you think it would take 30 lunch times to get from the bottom of the stairs to the top? Of course, not. That doesn’t make sense, does it? That’s a silly answer. This isn’t the best estimate at all.

The answer is going to have to be 30 minutes or 30 seconds. Which is the best estimate? Well, we know that there are 60 minutes in an hour, so 30 minutes is half of an hour. Does this sound right, that you start climbing the stairs and then half an hour later, you reach the top?

Well, what about 30 seconds? We know that 30 seconds is about the length of time it takes to count to 30. Which units of measurement would make the best estimate? It’s 30 seconds, isn’t it? If we started counting from 1 to 30, it makes sense that we might reach the top of the stairs by the time we got to 30. 30 minutes and 30 hours are far too long. The best estimate for the amount of time it would take to climb a flight of stairs is 30 seconds.

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