A helicopter covers its outward journey at 330 mph. It returns over exactly the same distance at 165 mph. What is the helicopters average speed over the entire journey? The answer is 220, but how? I got these cards fun, but some are really hard! Thank you for your answers.
the length of the journey is irrelevant, that's the point of the question, to realise what are the salient factors, this is not primarily about the arithmetic. The journey back always takes double the journey there, let's call the distance D, the average speed A and the Time T, so the total journey takes 3T thus: A=2S/3
And I would add it's not a matrix PP, it's a 3x3 table. It's also some while since I did matrices but certainly never added or worked with individual entries in a single matrix.
1965 Townend called it a matrix
and thanks for the ref/url - - - I just cant see the table or matrix
a matrix is what you say it is innit?
"In mathematics, a matrix is a rectangular array or table of numbers, "
oh lardee daa - I have been Newton heath far too long - like Hazza I am imprisoned but do not know it. And Prood is my Meghan or muse - er what colour are you by the way?
apg: "Just to clarify, in my original reply I did say that the distance was variable , meaning it did not matter in the equation and was irrelevant. Something obviously got lost in translation." - yes the correct answer and method for a start!
apg: "It doesn't matter how long the journey was or what distance, as the average MPH will be the same whether the journey was 10 miles or 1000 miles, and it can be worked out using Algebra - kerching! " - the penny drops, a long way!