Question
A boat covers 35 km downstream in 2 h and covers the
same distance upstream in 7 h. Find the speed (in km/h) of the boat in still water.Solution
ATQ, Let the speed of boat in still water be x km/hr Speed of stream = y km/hr Speed upstream = (x - y) km/hr (x - y) = 35/2 = 17.5Â Â Â ----(1) Speed downstream = (x + y) km/hr (x + y) = 35/7 = 5Â Â Â Â ----(2) From (1) and (2), we get x = 11.25 km/hr Speed of boat in still water = 11.25 km/hr
24, 42, 60, ?, 96, 114
What will come in place of (?) question mark in the given number series.
10, 17, 26, 37, 50, ?
660, 653, 639, 618, 590, ?
What will come in place of the question mark (?) in the following series?
75, 219, 388, ?, 809, 1065168, 178, ?, 273, 400, 618, 963
60   61    57   66    ?      75    39
...What will come in place of the question mark (?) in the following series?
2, 5, 14, 41, 122, 365, ?
81, 83, 87, 95, 111, ?
What will come in place of the question mark (?) in the following series?
400, 841, 1202, ?, 1716, 1885
64, 66, 69, 74, 81, ?
