Question
A car moves from city ‘A’ to city ‘B’ at 50 km/h
and returns back from city ‘B’ to city ‘A’ at 75 km/h. Find the car’s average speed during the entire round trip.Solution
ATQ,
Let the distance between city ‘A’ and ‘B’ = D km
Average speed = Total distance / Total time
Average speed = (D + D) / [(D / 50) + (D / 75)]
= 2D / [(3D + 2D)/150]
= 2D / (5D / 150)
= (2D / 5D) × 150
= 60 km/h
4, 4, 12, 60, ?, 3780
18, 10, 12, 21, ?, 120
What will come in place of the question mark (?) in the following series?
10, 410, ?, 710, 760, 785
380, ?, 360, 324, 260, 160
What will come in place of the question mark (?) in the following series?
45, 66, 44, 67, 43, ?
1024, 256, 768, 192, 576, 144, ?
12, 13, 27, 82, 329, ?
8, 15, 44, 175, 874, ?
290, 571, 900, ?, 1485, 1890
18 19 34 111 428 2165 ?
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