Question
A man goes downstream with a boat to some destination
and returns upstream to his original place in 5 hours. If the speed of the boat in still water and the stream are 10km/h and 4km/h respectively, the distance of the destination from the starting place is.ÂSolution
Let the speed of boat in still water =B and speed of stream =S then Given – B=10km/h, S=4km/h Speed of boat in downstream =B+S=10+4=14 B+S=14          … (1) Speed of boat in upstream =B-S=10-4=6 B-S=6 … (2) Average speed = (14×6)/14+6 =84/20=4.2km/h now the distance of the destination from the starting place is. =5×4.2 =21km.
- 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
