Question
Motor boat covers a certain distance downstream in a
river in 20 hours. It covers the same distance upstream in 30 hours. If the speed of the water is 12 km/hr, then the speed of the boat in still water is:Solution
Let the distance be ‘D’ km According to the question, Downstream speed x + y = d/20 or d = 20 (x+y) .......... (i) Upstream speed x-y = d/30 or d = 30(x-y) ........... (ii) Comparing (i) & (ii) 20(x+y) = 30(x-y) 2(x+y) = 3(x-y) 2x + 2y = 3x - 3y x = 5y Hence, y = Speed of the current = 12 km/hour. Speed of boat, x = 5 × 12 = 60 km/hr
I sit behind the counter and wait for a customer to come in and by something, but they all walk past the window as though the place were invisible.
...      Select the Incorrectly spelt word.
Choose the word with correct spelling.
Pakistan has issued over 3,800 visas to Indian pillgrims for participating in the 549th birth anniversary of Guru Nanak in Nankana Sahib near Lahore fro...
Four words are listed below. Select the CORRECTLY spelt word.
In each group, one word is correctly spelt. Find the correct word.
Choose the correct spelling of the words below.
In each group, one word is correctly spelt. Find the correct word.
Select the correctly spelt word.
As she sat in a New York City courtroom hearing the unanimos (A) verdict (B) of a jury that found her guilty (C) of crimes, the British socialite did no...
Relevant for Exams:
