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Help with the Speed Distance Time questions for the RAF CBAT

I've been preparing for the RAF CBAT recently and have been having some problems with the speed distance and time questions on www.speeddistancetime.info. Basically, I understand how to calculate Speed for this format (when you put the two numbers into a fraction, find the lowest common multiple between them, work out how many go into 60 etc etc) But I've been struggling to find anything that can tell me how to work out Distance and Time. I have done loads of searching but it appears everyone just gives the same method which wouldn't work for the cbat since it would take a long time to find the answer without the help of a calculator. I've come across one person on this forum who gave a fairly detailed description for how to work out speed distance and time, but their method for Time was slightly confusing in the way they worded it, and their method for Distance (Distance = Speed x Time) would be almost impossible to work out without a calculator unless you had really easy numbers to work with.

Sorry for the paragraph, but in short I understand the basic equations for Speed Distance and Time, however it seems you can't use these without using a calculator for some of the questions on the practice site I've been using. So, If someone could explain how to quickly and accurately work out Distance and Time without a calculator it would be greatly appreciated.

Here are some example questions to give you an idea of what I'm working with:
-At 20 mph, how long does it take to travel 12 miles?
-At 156 mph, how long does it take to travel 26 miles?
-At 70 mph, how long does it take to travel 112 miles?
-At 15 mph, how long does it take to travel 32 miles?
-At 16 mph, how far do you travel in 4 hours and 40 mins?
-At 35 mph, how far do you travel in 24 mins?
-At 24 mph, how far do you travel in 2 hours and 50 mins?
-At 48 mph, how far do you travel in 2 hours and 20 mins?
(edited 3 years ago)
Original post by Harvesteyo
I've been preparing for the RAF CBAT recently and have been having some problems with the speed distance and time questions on www.speeddistancetime.info. Basically, I understand how to calculate Speed for this format (when you put the two numbers into a fraction, find the lowest common multiple between them, work out how many go into 60 etc etc) But I've been struggling to find anything that can tell me how to work out Distance and Time. I have done loads of searching but it appears everyone just gives the same method which wouldn't work for the cbat since it would take a long time to find the answer without the help of a calculator. I've come across one person on this forum who gave a fairly detailed description for how to work out speed distance and time, but their method for Time was slightly confusing in the way they worded it, and their method for Distance (Distance = Speed x Time) would be almost impossible to work out without a calculator unless you had really easy numbers to work with.

Sorry for the paragraph, but in short I understand the basic equations for Speed Distance and Time, however it seems you can't use these without using a calculator for some of the questions on the practice site I've been using. So, If someone could explain how to quickly and accurately work out Distance and Time without a calculator it would be greatly appreciated.

Here are some example questions to give you an idea of what I'm working with:
-At 20 mph, how long does it take to travel 12 miles?
-At 156 mph, how long does it take to travel 26 miles?
-At 70 mph, how long does it take to travel 112 miles?
-At 15 mph, how long does it take to travel 32 miles?
-At 16 mph, how far do you travel in 4 hours and 40 mins?
-At 35 mph, how far do you travel in 24 mins?
-At 24 mph, how far do you travel in 2 hours and 50 mins?
-At 48 mph, how far do you travel in 2 hours and 20 mins?

I'm not amazing at maths but I have a method that worked for me on the CBAT. I used that same website to practice and just did a little each day and found that the questions on the real thing were slightly easier than that website which is good as you want to train hard and fight easy. I normally find a ratio/percentage in my head, it seems tricky at first but if you do 30 mins or so a day you begin to see patterns and you get quicker (surprise surprise its just like my teachers used to tell me over and over!) I've tried to explain it fairly clearly below but I'm no teacher so if anything's unclear let me know and I'll try to expand on it.

For the first example I'll use "At 20 mph, how long does it take to travel 12 miles?"
At 20 mph it will obviously take 60 mins to travel 20 miles. 30 mins for 10. 15 mins for 5. 3 mins for 1.
Therefore, 12 miles is 10 miles +1 mile+1 mile. Going by what I have worked out above that's 30mins+3mins+3mins which is 36 mins.
Therefore, it takes 36 mins to travel 12 miles.
That may seem long-winded and it probably is, but its simple and you can do it fast once you practice it.

For distance I'll use "At 16 mph, how far do you travel in 4 hours and 40 mins?"
At 16 mph you will travel 16 miles in 60 minutes. 8 miles in 30. 4 miles in 15. 2 miles in 7.5. 1 mile in 3.75. But also 40 minutes is a nice number as it is 2/3rds of 60. Therefore you need to find 2/3rds of 16. 1/3rd of 16 is 5.3 recurring and so we times that by 2 and get 10.6 recurring.
Therefore, if 4 hours and 40 mins is 60+60+60+60+(2/3rds of 60) then going by what I have worked out above I know that it is 16+16+16+16+10.6 recurring which equals 74.6 recurring
Therefore, you travel 74.7 miles (3 sig fig).

I'm 90% sure you wont have to deal with recurring numbers and rounding on the CBAT from what I can remember but it helps to know how to deal with them in case I'm wrong! Once again I don't claim this is the best way of doing it but it worked for me. Try a bunch of different methods not just one and see what works best for you - every brain is different.
Reply 2
Here's a good one to melt the brain.

You have to travel a distance of 2 miles at an average speed of 60mph. You travel the first mile and your average speed is only 30mph. How fast do you have to travel the second mile to have the overall average of 60mph?
Reply 3
Original post by cookie_slap
I'm not amazing at maths but I have a method that worked for me on the CBAT. I used that same website to practice and just did a little each day and found that the questions on the real thing were slightly easier than that website which is good as you want to train hard and fight easy. I normally find a ratio/percentage in my head, it seems tricky at first but if you do 30 mins or so a day you begin to see patterns and you get quicker (surprise surprise its just like my teachers used to tell me over and over!) I've tried to explain it fairly clearly below but I'm no teacher so if anything's unclear let me know and I'll try to expand on it.

For the first example I'll use "At 20 mph, how long does it take to travel 12 miles?"
At 20 mph it will obviously take 60 mins to travel 20 miles. 30 mins for 10. 15 mins for 5. 3 mins for 1.
Therefore, 12 miles is 10 miles +1 mile+1 mile. Going by what I have worked out above that's 30mins+3mins+3mins which is 36 mins.
Therefore, it takes 36 mins to travel 12 miles.
That may seem long-winded and it probably is, but its simple and you can do it fast once you practice it.

For distance I'll use "At 16 mph, how far do you travel in 4 hours and 40 mins?"
At 16 mph you will travel 16 miles in 60 minutes. 8 miles in 30. 4 miles in 15. 2 miles in 7.5. 1 mile in 3.75. But also 40 minutes is a nice number as it is 2/3rds of 60. Therefore you need to find 2/3rds of 16. 1/3rd of 16 is 5.3 recurring and so we times that by 2 and get 10.6 recurring.
Therefore, if 4 hours and 40 mins is 60+60+60+60+(2/3rds of 60) then going by what I have worked out above I know that it is 16+16+16+16+10.6 recurring which equals 74.6 recurring
Therefore, you travel 74.7 miles (3 sig fig).

I'm 90% sure you wont have to deal with recurring numbers and rounding on the CBAT from what I can remember but it helps to know how to deal with them in case I'm wrong! Once again I don't claim this is the best way of doing it but it worked for me. Try a bunch of different methods not just one and see what works best for you - every brain is different.

Thank you very much for your reply, you didn't have to put that much effort in and you described your method very clearly so I appreciate that. I will definitely try to practice this method from now on.

I have just one question for you if you don't mind. If you can remember, would you say the SDT questions in the CBAT are similar to the examples I gave you, or would you say they are more simple in terms of them using smaller and easily divisible numbers or simple times like hours and half hours, as opposed to times such as 25 minutes or 43 minutes? Thanks
Original post by Harvesteyo
Thank you very much for your reply, you didn't have to put that much effort in and you described your method very clearly so I appreciate that. I will definitely try to practice this method from now on.

I have just one question for you if you don't mind. If you can remember, would you say the SDT questions in the CBAT are similar to the examples I gave you, or would you say they are more simple in terms of them using smaller and easily divisible numbers or simple times like hours and half hours, as opposed to times such as 25 minutes or 43 minutes? Thanks

I did it almost two years ago so I can't remember for sure and please do not take what I am about to say as gospel as I may be misremembering somethings but I distinctly remember feeling slightly relieved that the questions weren't as hard as that website but I was really glad I had used it for practice as it had got my abilities to a level higher than what was needed for the test so it almost seemed like a breeze. If I had to ballpark the actual difficulty there were no decimals or awkward numbers so it was basic math but you had to work fast as you had a limit per question or something (Once more I am not 100% sure if I am remembering right though so hopefully someone who has done the CBAT more recently can clarify for you. Think someone on here was taking questions having just done it a few weeks ago). One thing that did happen though was that on a couple of them there would be a storm cloud halfway along the route your plane was travelling which halved your speed or something like that so it would effectively ask: How long does it take to travel 10 miles if you travel at 10 mph for 5 miles then 5mph for 5 miles. Also for each scenario it told you how heavy your aircraft was and you had to look at a table which told you how fast you could travel at different speeds then eventually they start telling you that you have packages to pick up or deliver along your route so as you go you will eventually speed up and slow down and you have to remember to check the table to work our your new speed.
(edited 3 years ago)
Reply 5
Original post by cookie_slap
I did it almost two years ago so I can't remember for sure and please do not take what I am about to say as gospel as I may be misremembering somethings but I distinctly remember feeling slightly relieved that the questions weren't as hard as that website but I was really glad I had used it for practice as it had got my abilities to a level higher than what was needed for the test so it almost seemed like a breeze. If I had to ballpark the actual difficulty there were no decimals or awkward numbers so it was basic math but you had to work fast as you had a limit per question or something (Once more I am not 100% sure if I am remembering right though so hopefully someone who has done the CBAT more recently can clarify for you. Think someone on here was taking questions having just done it a few weeks ago). One thing that did happen though was that on a couple of them there would be a storm cloud halfway along the route your plane was travelling which halved your speed or something like that so it would effectively ask: How long does it take to travel 10 miles if you travel at 10 mph for 5 miles then 5mph for 5 miles. Also for each scenario it told you how heavy your aircraft was and you had to look at a table which told you how fast you could travel at different speeds then eventually they start telling you that you have packages to pick up or deliver along your route so as you go you will eventually speed up and slow down and you have to remember to check the table to work our your new speed.

Alright thanks that's been a great help. Hopefully the questions are a bit easier so practicing on the website will make the real thing feel more relaxed. I've also been practicing questions similar to what you described about having to stop to pick up packages and taking the different speeds into account so that's given me a bit of confidence.
90mph?

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