Question
The downstream speed of a boat is 75% greater than its
upstream speed, and the speed of the stream is 3 m/s. How far can the boat travel in still water in 7.5 hours?Solution
Let the speed of boat in still water is y m/sec Then according to question (y+3) = 175% of (y-3) 4y+12 = 7y-21 3y = 33 Y = 11 m/sec Y = 11×18/5 km/hrs. = 198/5 km/hrs. boat can cover the distance in still water in 7.5 hours = 198/5 ×7.5 = 297 km
5, 18, 39, 68, 105, ?
230 192 172 ? 122 100
...5, 6, 14, 45, 184, ?
15, 23, 30, 36, 41, ?
3, 8, 27, 124, ?
1236, 1445, 1675, 1933, 2226, ?
13, 29, 65, 129, ?, 373
12, 33, 45, 78, 123, 201, ?
What will come in place of the question mark (?) in the following series?
36, 85, ?, 230, 330, 451
250, 279, 311, 349, 396, ?