Theory question 102
Ratio, Percentages and RatesTwo cars X and Y, start from a common point and travel in opposite directions. X travels at an average speed of 60 km/h and Y at 80 km/h on the same course.
(a) Determine, how far apart X and Y will be after 3 hours
(b) If the speed of X is increased by 20 km/h within the 3 hours, what would be the effect on the distance between X and Y? (c) State the importance of considering speed when calculating total distance over the same time frame
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(a) X: 60 × 3 = 180 km; Y: 80 × 3 = 240 km; apart = 420 km
(b) X: 80 × 3 = 240 km; apart = 240 + 240 = 480 km, an increase of 60 km
(c) Distance = speed × time, so for the same time a higher speed gives a greater distance (the separation grows with the combined speed)
Moving in opposite directions, add the distances.