since time = distance/speed,
350/x = (470-350)/(x-15)
Kate cycles the first 350 km of a 470 km journey at a certain average speed and the remaining distance at an average speed that is 15 km/h less than that for the first part of the journey. If the time taken for her to travel each part of her journey is the same, find the average speed for the second part of her journey.
8 answers
Let "x" be the average speed during 1st part of the journey, thus,
(x-15) be the average speed during other part of the journey.
Time Taken for 1st Part of Journey = 350 / x = 350/x hrs and
Time Taken for the 2nd part = (470-350) / (x-15) = 120 / (x-15) hrs
Since time taken for both the journeys, therefore,
350 / x = 120 / (x-15)
350(x-15) = 120x
350x-5250 = 120x
350x-120x = 5250
230x = 5250
x = 5250/230
x = 525/23 = 22.83 km/hrs approx. be the average speed for 1st journey thus x-15 = 22.83-15 = 7.83 km/hr is the average speed for the 2nd journey and hence this is the answer.
(x-15) be the average speed during other part of the journey.
Time Taken for 1st Part of Journey = 350 / x = 350/x hrs and
Time Taken for the 2nd part = (470-350) / (x-15) = 120 / (x-15) hrs
Since time taken for both the journeys, therefore,
350 / x = 120 / (x-15)
350(x-15) = 120x
350x-5250 = 120x
350x-120x = 5250
230x = 5250
x = 5250/230
x = 525/23 = 22.83 km/hrs approx. be the average speed for 1st journey thus x-15 = 22.83-15 = 7.83 km/hr is the average speed for the 2nd journey and hence this is the answer.
Wrong answer is 7 19/23
home work kar liya
how did you get the ans 7 19/23 that is the correct answer can u pls teach me
Saleem is correct the question is in my book and his answer is the same as the answer at my key answer
both answers are correct
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1 answer