Can someone explain this?

[dsryan1]

I'm currently working on my maths and seem to have hit a wall with speed / distance x time. Can't find much on the internet regarding this.

speed = distance / time
distance = speed * time
time = distance / speed

Now, for example, what if the question was as follows;

A car has travelled 62 miles and the journey has taken 45 minutes.

Answer using this method: 62/45 = 1 r 17

How can I get the speed? What is the further step here? I understand this method works if you write it in hours, but it doesn't work in minutes. How can I make all of these methods work in minutes?

 

[HallsofIvy]

I'm currently working on my maths and seem to have hit a wall with speed / distance x time. Can't find much on the internet regarding this.

speed = distance / time
distance = speed * time
time = distance / speed

Now, for example, what if the question was as follows;

A car has travelled 62 miles and the journey has taken 45 minutes.

Answer using this method: 62/45 = 1 r 17

How can I get the speed? What is the further step here? I understand this method works if you write it in hours, but it doesn't work in minutes. How can I make all of these methods work in minutes?

That's a perfectly good answer! The speed is 1 and 17/45 miles per minute. You want it I miles per hour?
Surely you know that there are 60 minutes in an hour!? 45 minutes is 45/60= 3/4 of an hour. If you go 62 miles in 3/4 hour, how many miles per hour are you doing?

Another way to do this is to note that 1 and 17/45 miles per minute times 60 minutes per hour will give (1 and 17/45)(60) miles per hour since the "minutes in the denominator" of 1 and 17/45 miles per minure will cancel the "minutes in the numerator" of 60 minutes per hour.

 

[dsryan1]

That's a perfectly good answer! The speed is 1 and 17/45 miles per minute. You want it I miles per hour?
Surely you know that there are 60 minutes in an hour!? 45 minutes is 45/60= 3/4 of an hour. If you go 62 miles in 3/4 hour, how many miles per hour are you doing?

Another way to do this is to note that 1 and 17/45 miles per minute times 60 minutes per hour will give (1 and 17/45)(60) miles per hour since the "minutes in the denominator" of 1 and 17/45 miles per minure will cancel the "minutes in the numerator" of 60 minutes per hour.

So, excuse me if I'm sounding silly here, but I take 1.17 and times it by 60 and I'll have it in mph?

Edit:- Just read the bottom part. For some reason it didn't load fully, hence me having to edit this reply.
So, 1.17x60 wouldn't be sufficient? I'm very confused! Extremely rusty with maths.

 

[Ishuda]

So, excuse me if I'm sounding silly here, but I take 1.17 and times it by 60 and I'll have it in mph?

First that is not a 1.17, it is a 1 with remainder 17, 1 r 17 which translates to about 1.3778.

Doesn't that sound reasonable? If you traveled 62 miles in 45 minutes, wouldn't you expect to travel about about 1/3 that distance in 1/3 the time or about 82+ miles in one hour.

 

[dsryan1]

First that is not a 1.17, it is a 1 with remainder 17, 1 r 17 which translates to about 1.3778.

Doesn't that sound reasonable? If you traveled 62 miles in 45 minutes, wouldn't you expect to travel about about 1/3 that distance in 1/3 the time or about 82+ miles in one hour.

Yep, and having done the calculation of 1.3778 x 60 it got the answer bang on. How did you translate the remainder 17?

Forgive me if I sound difficult here, I'm trying to build a method of stages in which I can follow to answer many questions this way.

 

[dsryan1]

I'm trying to get the exact mph (that being 82.6) and form some sort of method to get it right every time. I'll be sitting a test with similar questions and it requires you to know the exact speed. For example, 82.6 must be written that way as opposed to 82+.

So could you share with me how you translated the remainder?

I'll then use the following method for every sum, if it sounds like a decent idea?

1). Divide the sum as normal, for example 62/45.
2). Take the answer of 1 remainder 17.
3). Translate the remainder into a number that can be joined to the 1 (for example: 1.3778)
4). Times that answer by 60 to get the final answer.

 

[Ishuda]

Yep, and having done the calculation of 1.3778 x 60 it got the answer bang on. How did you translate the remainder 17?

Forgive me if I sound difficult here, I'm trying to build a method of stages in which I can follow to answer many questions this way.

I wasn't sure what the answer [ 1 r 17 ] referred to and guessed - turned out to be right. However, I have seen answers referred to that way in the past, just didn't expect it there.

Speaking of building a method of stages, look at the units in the examples. It helps a lot of times in the problem. For example if you have miles and hours and want miles per hour, you know you will have to divide the miles number by the hrs number.

 

[HallsofIvy]

I'm trying to get the exact mph (that being 82.6) and form some sort of method to get it right every time. I'll be sitting a test with similar questions and it requires you to know the exact speed. For example, 82.6 must be written that way as opposed to 82+.

Well, there's your first problem: "82.6" is NOT "the exact mph". The exact speed, 62 miles divided by 3/4 hour is 62 times 4/3= (62(4))/3= 248/3= 82 and 2/3. That can be written as a decimal only with a repeating decimal: 82.6666666... where the "..." indicates that the "6" keeps repeating forever.

So could you share with me how you translated the remainder?

I'll then use the following method for every sum, if it sounds like a decent idea?

1). Divide the sum as normal, for example 62/45.
2). Take the answer of 1 remainder 17.
3). Translate the remainder into a number that can be joined to the 1 (for example: 1.3778)
4). Times that answer by 60 to get the final answer.

 

[HallsofIvy]

Yep, and having done the calculation of 1.3778 x 60 it got the answer bang on.

No, it does not give the answer "bang on". 1.3778 x 60= 82.668 which is NOT the exact answer nor is it the "82.6" you stated before was the exact answer. The exact answer is 82 and 2/3 miles per hour as I said before.

How did you translate the remainder 17?

Forgive me if I sound difficult here, I'm trying to build a method of stages in which I can follow to answer many questions this way.

 

[Probability]

I'm currently working on my maths and seem to have hit a wall with speed / distance x time. Can't find much on the internet regarding this.

speed = distance / time
distance = speed * time
time = distance / speed

Now, for example, what if the question was as follows;

A car has travelled 62 miles and the journey has taken 45 minutes.

Answer using this method: 62/45 = 1 r 17

How can I get the speed? What is the further step here? I understand this method works if you write it in hours, but it doesn't work in minutes. How can I make all of these methods work in minutes?

Sometimes it might be easier to stick to the SI Units systems.

V = Velocity (speed) ms^-1
S = Distance (metres) m
t = Time (seconds)

Formula

V = (s) / (t)

V = 62 / 0.75

V = 82.6 mph (recurring)

The normal rule here is 5 or more round up so the answer would be 83 mph

When evaluating time convert to decimal hours by dividing the minutes given in the question by 60, then following the example here gives the speed.

I confess I have no idea why you would want an answer for speed as 1 r 17?

Why would you want a remainder and why a speed answer in that format?