deltanova Posted April 29, 2006 Share Posted April 29, 2006 i have been given this question as part of a maths assignment so i dont want to be put into a situation where i might be advantaged against my other classmates with too much extra help but i was wondering if anyone could help me define y in this, im pretty confident that i have the right answer. i just cant think of the words to define it. A motorist covered the first third of the distance at 60km/hr and the next third at 90km/hr. If the average speed for the whole trip was 80km/hr, what was the speed for the final third of the trip? Here is my answer: [math] \frac{y}{3} [/math] =80 y= 240 60+90+x=240 150+x=240 x=90 the speed for the last third of the trip was 90km/hr i have tried to define y myself as the total of all speeds, can anyone offer a better clearer more precise one? cos im stuck Link to comment Share on other sites More sharing options...
Cloud Posted April 29, 2006 Share Posted April 29, 2006 Yeah - you're right. There's nothing much more you can to do. The mean will always be inaccurate anyway so there isn't a clearer precise answer. 90 km/hr is correct. Link to comment Share on other sites More sharing options...
deltanova Posted April 29, 2006 Author Share Posted April 29, 2006 Ahhh so thats what y is, the mean? thanks loads cloud, i owe ya one only two questions left and my assignments finished thanks loads Link to comment Share on other sites More sharing options...
Cloud Posted April 29, 2006 Share Posted April 29, 2006 No - the y isn't the mean The mean (average) is 80 km/hr y is just the constant that is needed in order to carry out a division of 3 to obtain the mean. Which you've done. Link to comment Share on other sites More sharing options...
deltanova Posted April 29, 2006 Author Share Posted April 29, 2006 oh oki doke, good to know i know what im doing hehe. (im amazed i got the answer right first time) Link to comment Share on other sites More sharing options...
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