IF a catamaran travel at a speed of 20 km per hour in stillwater. So when it travel at a downstream speed 5 kilometre per hour. What will be the time taken by it to travel 90 km.

Since the catamaran is travelling in downstream the speed of the stream as a pin the speed of the ship so its speed is equals to catamaran speed+downstream speed. Which becomes 20+5=25 km/he. Now by applying a formula we get

Time=90/25. We get our answer which is 3.6

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In following questions, one term in number series is incorrect.

Find out the incorrect number 15, 16, 22, 29, 45, 70

Find out the incorrect number 15, 16, 22, 29, 45, 70

The pettern is + 1, + 4, + 9, + 16, + 25,.... i.e. + 1

So, 22 is wrong and must be replaced by (16 + 4) i.e. 20..

In alphabet series, some alphabets are missing which are given in that order as one of the alternatives below it. Choose the correct alternative.

a _ bc _ a _ bcda _ ccd _ bcd _

The series is aabcd / abbcd / abccd / abcdd.

Thus, a, b, c and d are repeated twice one by one.

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In alphabet series, some alphabets are missing which are given in that order as one of the alternatives below it. Choose the correct alternative. b _ abbc _ bbca _ bcabb _ ab

The series is bcab / bcab / bcab / bcab / bcab. Thus, the pattern bcab is repeated.

In alphabet series, some alphabets are missing which are given in that order as one of the alternatives below it. Choose the correct alternative.

adb _ ac _ da _ cddcb _ dbc _ cbda

The series is adbc acbd abcd dcba dbca cbda.

Thus, the letters equidistant from the beginning and the end of series are the same.

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Excluding stoppages, the speed of train is 50 km per hour and including stoppages it is 40 km per hour. For how many minutes does the train stop per hour?

Due to stopages it is it covers 10 km less.

Time taken to cover 10 km= (10/50)*60 min = 12 min

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In Math test out of 10 marks for students got 4 marks and 6 got 5 marks what will be the average marks of class:

={( number of student X marks)+( number of student X marks)}/ total students

={( 4 x 10)+(6Ã—5)}/6+4

=(40+30)/10

= 7 is the average marks of class.

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