Question
A boat travels 42 km against the current and 72 km with
the current in a total time of 8 hours. Additionally, it covers a distance of 56 km in still water in 4 hours. Given that the speed of the current exceeds 1.75 km/h, by what percentage is the boat's speed upstream lower than its speed downstream?Solution
Speed of the boat in still water = 56/4 = 14 km/h Let the speed of the stream = x km/h So according to question: 42/(14 – x) + 72/(14 + x) = 8 294 + 21x + 504 –36x = 784 – 4x2 4x2 – 15x + 14 = 0 4x2 – 8x – 7x + 14 = 0 4x(x – 2) – 7(x – 2) = 0 (4x – 7)(x – 2) = 0 x = 2, 7/4 = 2, 1.75 As the speed of the stream is greater than 1.75, the value of x = 2 So the downstream speed and upstream speed of the boat are 16 km/h and 12 km/h respectively. So the desired percentage = (16 – 12)/16 × 100 = 25%
If you want to be a politician, you'll do much better if you were born with the gift of gab .
- In each question, five alternatives are given for the Idiom/Phrase given in bold in the sentence. Choose the alternative which best expresses the meaning o...
Select the idiom/phrase that most accurately and contextually replaces the bolded segment.
He keeps trying to get the company to reconsider th...
Select the idiom/phrase that most accurately and contextually replaces the bolded segment.
The CEO deliberately avoided addressing the core f...
Which word or words explain the meaning of the following idioms;
Down In the drumps
Directions: In the given questions, a statement with a blank is given. Fill the blank with the most suitable idiom/phrase to make the statement meaning...
Break the bank
Fill in the blank with an appropriate idiom.
The couple was __________, but they eventually got their act together.
In each of the following questions, an idiomatic expression/a proverb has been underlined – followed by four alternatives. Choose the one which best ...
Reap the whirlwind
Relevant for Exams:
