Speed Distance Time for Dummies

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First break it down to something you can work with

So 425/5 = 85

170 = 2x 85

Would take 2 hours at 85mph but since your going 5 times as fast you'll do it in a 1/5 of the time

24 mins?

Reply 61

Lady Venom

425 in 60
42.5 in 6 mins
7ish in 1min

170/7 = 24ish.

Reply 62

username163970

S = D/T

so if D = 33miles and T = 36mins, what is S?

Reply 63

threeportdrift

Careers Forum Helper

What do you do to T to make it 60 (ie an hour)?

Then do the same to 33.

Reply 64

Lady Venom

33 = 36
x = 60

You need to find out what distance you will cover in 1 hour to get the speed in MPH.

I can see that 3 is a common denominator:

36/3 = 12 - I know that 12x5 = 60

So:

33/3 = 11x5 = 55 <-- Answer

Play with common numbers... it works!

You can also see with this example that your answer is going to somewhere in the 50's i.e. close to the whole hour so you can the check that your answer is at least in the right ballpark.

Reply 65

username163970

At 128 mph, how long does it take to travel 320 miles?

Reply 66

Sandy391

320-(128 x 2)=
320 - 256 = 64

64 is .5 of 128

so 2.5 hours

Reply 67

Lady Venom

As that man said ^

Easy. Just break it all up....

Reply 68

username163970

Ajvir

320-(128 x 2)=
320 - 256 = 64

64 is .5 of 128

so 2.5 hours

why did u multiply by 2??

Reply 69

threeportdrift

Careers Forum Helper

That's one of the problems with using a forum like this for these questions. People do maths in different ways, for example I see all the numbers as pictures, even colours on a clock face, I just know immediately that 15 = 1/4, 20 = 1/3, 40 = 2/3 etc.

I did the sum in my head in a few seconds, but when I looked at Ajvir's solution it took me ages to work out how on earth he had figured it out - because he obviously does his maths in a very different way to me.

Best ways I have found to practice SDT sums are:

a) If you drive/pax in a car with Satnav you can keep doing sums based on distance to go and ETA and calculate your average speed.

b) On the treadmill, while slogging out those training miles you can do all sorts of mental arithmetic about miles per hour, seconds per 100m, metres per minute, if I stick at this rate how long will it take me to do 3 miles, 6 miles etc.*

It doesn't matter that it isn't on the scale of aircraft speeds etc, it gets you used to working in base 60. And you have to practice the way you do maths, not try and re learn someone else's technique.

*Obviously, being ex-Hercs, I have never actually used a treadmill myself, I've just heard about them from the salad-munchers.

Reply 70

username163970

can anybody recollect and typical OASC SDT questions then?

Reply 71

Lady Venom

He multiplied like 2 because like me he probably sat and did 128x2 and at a quick glance I know it's around 260ish and if it was 128x3 at a glance thats easily over 360!

Reply 72

username163970

D = 90miles, S = 72mph

T = D/S = 90/72

72 = 6/5

90*5 = 450

450/6 = 75mins = 1hr 15mins

i'm getting there!

Reply 73

Sandy391

threeportdrift

That's one of the problems with using a forum like this for these questions.

Indeed, there are several different ways to do any one question, you just need to find the best one for you. Personally I quite enjoyed the maths based tests on aptitude, some were ridiculously easy, others were pushing on immensely difficult. I like to see what I am doing and seeing as you are allowed pen and paper for only of the tests this proved to be challenging. As silly as it sounds, I drew out the sum with my finger on the screen or on the desk, a little unorthodox but for me, it worked and I passed with a decent score. This is not to say it will work for everyone, you just need to find somehthing that will work for you!

Don't sweat it, you will be fine!

Reply 74

Sandy391

Yes, although it is hard to say as they range from as simple as 3x2 to:

'calculate how far an aircraft has travelled if it is burning x amount fuel (then you check a table they give you to work out what speed the plane is going) for 3 hours and y amount fuel for 2 hours.'