Question
A boat travels a certain distance downstream in 72
minutes but takes 3 hours to cover the same distance upstream. The speed of the stream is 15 km/h. If the boat's speed in still water were reduced by 20%, how much time (in minutes) would it take for the boat to travel 236.5 km downstream?Solution
Let the speed of boat in still water be 'x' km/h, respectively. ATQ, D = (x + 15) X 1.2 = 1.2x + 18 .......(i) Also, D = (x - 15) X 3 = 3x - 45 ........(ii) Solving equations (i) and (ii) , we get, 1.2x + 18 = 3x - 45 Or, 1.8x = 65 So, 'x' = (63/1.8) = 35 Therefore, required time = 236.5 ÷ (0.8 X 35 + 15) = (236.5/43) = 5.5 hour = 5.5 X 60 = 330 minutes
Before the recession, Ireland was on the pig's back , but the situation has changed drastically.
Read each sentence to find out whether there is any grammatical error in it. The error, if any, will be in one part of the sentence. Mark the part with...
He denied to have (A)/any part in writing the information packs (B)/and advertisements and said they (C)/were largely available when he arrived (D).
In the following sentence, four words or phrases have been underlined. One of them is incorrect. Select the INCORRECT word or phrase from the given opti...
Each of the following sentences has been divided into five parts (a), (b), (c), (d) and (e). One of these parts may contain a grammatical or idiomati...
The average American individually (A)/emit 10 times more carbon dioxide (B)/from fossil fuel use then (C)/ an Indian, and about three times (D)/as much ...
The following sentence has been divided into parts. One of them may contain a grammatical error. Select the part that contains the error from the given...
Identify the segment that contains a grammatical error. If there is no error, select 'No error'.
It is custom for the Ministry of external affair...
In each of the questions, a sentence has been divided into four parts, one of which may contain an error. Identify that fragment and mark it as your an...
Spot the grammatical errors in the given sentence. Mark the part with error as your answer. If there is no error, mark "No error" as the answer. (Ignor...