S/T/D help please!!

Discussion in 'Join the Army - Regular Officer Recruiting' started by Biscuits59, Jan 7, 2011.

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  1. Hi

    I have been using the RAF OASC Selection Tests but I struggle with out a calculator on some of the harder questions. The website is really good for questions but need some help with a way of working it in my head fairly quickly.

    Apoligies as this is probally really simple but I am a Former Army Commando so struggle with this sort of thing.

    All help is massively welcomed.

  2. I passed OASC in 1986 at Biggin Hill. I bought this book and it helped me with the old SDT. The tests at Cranwell are now all computer based but use the same questions as the paper tests I did back many moons ago.

    Good luck !

    Test Your Own IQ: Amazon.co.uk: Prof. Hans Eysenck: Books
  3. STD isnt that some thing you get for shagging without a condom.
  4. can't help you with STDs mate, best go see your Doctor......

    on a serious note, just keep doing the RAF ones over and over, one day you will have an epiphany and it will all come together.
    Until then, good luck.
  5. I came into the thread primed to make that joke and found some bastard had already beaten me to it!
  6. After a quick google I found this, if your struggling perhaps it might be worth forking out for it, I am sort of tempted just to see if its any good.


    Keep working on it! At my briefing the s/d/t stuff was quite easy, (whole numbers easily divisible), if this is for your briefing I honestly would not worry about it, its your board you need to study for, once you have seen what you need to improve from your briefing. Though I will add I recently did the AAC aptitude test up at RAF Cranwell and that s/d/t and fuel stuff was horrendously hard! Personally I have gone back to basics and seen a huge improvement just by sharpening up my times bloody tables!

    Good luck and keep at it!
  7. A few examples below on how I tackle such questions. It may not work for you and I am in no way saying which method is the best just thought I would show you how I do them.

    A Time type question = At 240mph, how long does it take to travel 30 miles?
    When asked to find the time I find how long it takes to do 1 mile then multiply it by the distance.
    So here I would divide 60 by 240 = 0.25 (which is 15 seconds ( 1/4 of 60))
    Then times 0.25 by 30 = 7.5 which is 7 minutes 30 seconds.

    Now this is fairly long winded method and it does become very tough when dealing with numbers that don't divide into 60 so if anyone else has a certain method for solving this type of question I would like to see it also :grin:

    A Speed type question:
    What speed covers 6 miles in 4 mins?
    Here I divide 60 by 4 = 15
    15 times 6 = 90mph

    A Distance type question:
    At 40 mph, how far do you travel in 1 hour and 21 mins?
    Straight away you can just focus on the 21 minutes because 1 hour *40mph = 40 miles
    Here I do the a similar thing to the time type of question 60/40 = 1.5 = 1 minute 30 seconds per mile
    because 21 is an odd number I round up 1 minute 30 seconds per mile to 3 minutes for 2 miles.
    21/3 = 7 *2 = 14
    40+14 = 54 miles

    These are the methods I take when tackling these questions, if anyone has an easier way to answer the questions I would be very interested to see it.

  8. Get to work on your 3, 6 and 12 times tables. Just about everything in navigation is based around the sexagesimal system, with a base of 60. So it stands to reason that S/D/T is going to be heavily influenced.

    60secs per 1 minute
    60 min per 1 hour.
    360 (60x6) degrees in a circle
    60min per 1 degree of arc
    1 min of arc of a subtended at the earth's surface (along a great circle)= 1 nautical mile

    Magic numbers are commonly used in navigation to make calculations a little more simple


    60mph = 1mile/min
    90 = 1.5

    etc. etc.

    For slower speeds, a common trick is to just divide one's speed by 10 to calculate how for you can travel in 6 mins. All of a sudden, calculating how far you'd travel in 24 min at a given speed is much easier ( S/10 x 4= D )
  9. No way! I haven't looked at the link, but I bet you can get everything you need from t'internet for nowt!
  10. Even SDT test kits :)
  11. Now to be pedantic, we stopped having Army Commando's along time ago, arn't you a bit old for this sort of thing.