Question
A boat can travel 38 km downstream in 57 min. The ratio
of the speed of the boat in still water to the speed of the stream is 3: 2. How much time will the boat take to cover 22 km upstream?Solution
Speed of downstream = D/T = 38 × (60/57) = 40 km/hr The ratio of the speed of the boat in still water to the speed of the stream = 3: 2 (3x, 2x) => 5x = 40 => x = 8 Speed of upstream = 3x – 2x = x = 8 km/hr Distance = 22 km Time = D/S = 22/8 = 2(3/4) hr = 2 hour 45 min
15, 31, 67, 131, ?, 375
84, 97, ?, 162, 214, 279
500, 250, 750, 375, 1125, 562.5, ?
48, 24.5, ?, 39.75, 81.5, 206.25, 621.75
418, 406, 430, 382, 478, ?, 670
What will come in place of the question mark (?) in the following series?
16, 16, ?, 96, 384, 1920
97, 106, ?, 195, 411, 460
What will come in place of the question mark (?) in the following series?
22, 25, 30, 37, 48, ?
12, 13, 27, 82, 329, ?
In each of the following number series, one term is missing. Find the missing term.
7, 14, 28, 56, 112, ?
