Question
A boat covers 180 km each in upstream and downstream in
a total time of 10 hours. It also takes 5 hours to travel 40 km upstream and 140 km downstream. How far will the boat travel in still water in 6 hours 20 minutes?Solution
ATQ,
Let speed of boat in upstream and downstream be ‘x’ km/h and ‘y’ km/h, respectively. So, 180/x + 180/y = 10…………..(1) And, 40/x + 140/y = 5……………….(2) Solving equation (1) and (2), we get x = 36 and y = 48 Speed of boat in still water = (36 + 48)/2 = 42 km/h 6 hour 20 minutes = 6 + 20/60 = 19/3 hours Desired distance = (19/3) × 42 = 266 km
Find the wrong number in the given number series.
120, 126, 138, 162, 220, 306
In each of the following giving number series, a wrong number is given. Find out the wrong number?
46 23 23 34.5 70 172.5
...23, 36, 53, 69, 95, 124, 155
Find the wrong number in the given number series.
253, 542, 216, 579, 179, 620
Find the wrong number in the given number series.
24, 120, 721, 5040, 40320, 362880
3, 4, 9, 28, 116, 566, 3397
2 4 11 37 150 771
...210, 140, 105, 84, 70, 63, 52.5
- Find the wrong number in the given number series.
9, 13, 22, 47, 96, 197 131, 212, 261, 286, 295, 299
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