Question
The speed of a boat in still water is twice the speed of
the current. The difference between downstream and upstream speeds is 16 km/h. If the boat spends 10 hours to travel the same distance 'q' km each way, find 'q'.Solution
ATQ, Let the speed of the stream = t km/h Speed of the boat in still water = 2t km/h Upstream speed of the boat = 2t – t = t km/h Downstream speed of the boat = 2t + t = 3t km/h Difference in Speed: - 3t - t = 2t = 16 km/h, so, t = 8 km/h Calculate the time for each distance 'q': 
- What will come in place of (?), in the given number series.
1, 4, 9, 16, ?, 36 {(12√5 + 6√5 )} ×{(10√5 - 5√5 )} - 8² + 6² = ?
11          20          ?             64          112        192
...350 435 367 ? 384 401
...0, 6, 24, ?, 120, 210
21, 37, 73, 137, ?, 381
What will come in place of the question mark (?) in the following series?
4, 11, 32, 95, 284, 851, ?
18, 34, 70, 134, ?, 378
120, 136, 111, 147, ?, 162
What will come in place of the question mark (?) in the following number series?
124, 131, 117, ?, 110, 145
