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    8) A Royal Navy Harrier flies a triangular navigation exercise achieving an overall average speed of 500 knots. The first leg is 500 miles at 400 knots. The second leg is 1 hour long and you fly at 600 knots. The final leg (leg 3) is 450 miles. Find the speed for the final leg (to the nearest knot).
    529 knots
    259 knots
    952 knots
    592 knots
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    Could anybody please explain to me how to do this question?
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    Will have a look tomorrow but going to guess 529!
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    This is a question where figuring out the answer to the exact value is impracticable and would take too much time, so you have to estimate.

    In the first leg, you're travelling for 1 hour 15 minutes at 400 knots to cover 500 miles.
    In the second leg, you're travelling for 1 hour at 600 kts to cover 600 miles.

    The final leg is 450 miles, travelling at 450 kts (1 hours journey) would bring the average speed down (below 500 kts).

    You have to compensate for travelling that 15 minutes longer at 400 kts on the first leg, but a speed of 592 would be too much, so the answer is 529.

    Trying to explain these things can be difficult, the more similar questions you do, the more you will understand!
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    Or, you could be really pedantic and say that since the RN no longer flies the Harrier the question is null and void
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    That is because there are so many questions which in the time frame given would be so impracticable to answer with such accuracy.
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    A Hunt Class MCMV’s patrol vessel averages 42 mph for 2½ hours and 50 mph for the next 1½ hours. How far does it travel overall?
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    The Commanding Officer of HMS Illustrious travels 217 miles to Portsmouth for a meeting with the Chief of the Defence Staff. He left at 0815 and must arrive by 1145. After travelling 100 miles, he notices that 2 hours have passed.

    1) Calculate the average speed at which he had intended to travel.

    60 mph 61 mph 62 mph 63 mph


    2) Calculate his actual average speed for the first 2 hours.

    49 mph 50 mph 51 mph 52 mph


    3) Calculate the average speed at which he will now need to travel for the remainder of the journey, if he wants to arrive on time.

    76 mph 77 mph 78 mph 79 mph


    4) Calculate his arrival time at Portsmouth, if he finds he cannot increase his speed and his present speed is maintained for the rest of the journey (to the nearest minute).

    12:35 12:36 12:34 12:33
 
 
 
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