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.
20    60      180      540     ?     4860
...2342 2223 2090 1943 1782 ?
...13 14 22.5 ? 120 363
...25Â Â Â Â Â Â Â Â Â Â 34Â Â Â Â Â Â Â Â Â Â 61Â Â Â Â Â Â Â Â Â Â 106Â Â Â Â Â Â Â Â 169Â Â Â Â Â Â Â Â ?
...85    135    172    ?     215    225
12, 6, 6, 9, 18, ?
96Â Â Â 111Â Â Â 131Â Â Â ? Â Â Â Â Â 186Â Â Â Â 221
61, 48, ?, 35, 87, 22
1.2Â Â Â Â Â Â Â 4.2Â Â Â Â Â Â Â Â ? Â Â Â Â Â Â Â Â Â Â Â 18.2Â Â Â Â Â Â Â 33.2 Â Â Â Â Â Â 56.2
...To find the Next number in the given series.
342 510 726 996 1326 ?
...
