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A car covers the first half of the distancebetween the two places at 40 km/h andanother half at 60 km/h. The average speed ofthe car is:(a) 40 km/h(b) 48 km/h(c) 50 km/h(d) 60 km/h |
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Answer» let x/2 distance COVER in TIME t1 & another x/2 distance cover in time t2 t1 = (x/2)/40 t2 = (x/2)/60 t1+t2 = x/48 average speed = x/(t1+t2) = x/(x/48) = 48Km/hr (2) as the above t1 = x/40 t2 = x/60 t1+t2 = x/24 average speed = 2x/(x/24) =48Km/hr (3) S1 = 6*2 = 12Km. s2 = 4*3 = 12Km. total distance = s1+s2 = 24km. average speed = 24/5 = 4.8Km/hr |
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