Question
Covering 54 km upstream and 150 km downstream takes a
boat 8 hours in total. The boat’s still-water speed is 18 km/h more than the stream. What is the stream speed?Solution
Let the speed of the stream = x And the speed of the boat in still water = x + 18 54/(x + 18 − x) + 150/(x + 18 + x) = 8 54/18 + 150/(2x + 18) = 8 3 + 150/(2x + 18) = 8 150/(2x + 18) = 5 2x + 18 = 150/5 2x + 18 = 30 2x = 12 x = 6 The speed of the stream = 6 km/hr
Select the option in which the numbers are related in the same way as are the numbers of the following set.
(25, 18, 225)
Look at the below pattern and complete the series: 11, 15, 22, 26, 33, 37, 44, ?
Which of the following numbers will replace the question mark (?) in the given series?
69, 70, 74, 83, ?, 124
A series is 11, 20, 42, 82, 166, 330
If another series 4, a, b, c, d, 106 follows the same pattern as the given number series, then find the appr...
8, 7, 12, 35, 128, 635
8Â Â Â Â 20Â Â Â Â 36Â Â Â Â Â 56Â Â Â Â Â 80Â Â Â Â ?
16, 54, 128, ‘?’, 432,686
218, 108, 160, ? , 1385.50
12    16    43    ?       184    220
...6 16 ? 244 1,245 7,506 52,591
