Question
The duration it takes for boat 'P' to cover 160 km
downstream is equal to the duration it takes to cover 120 km upstream. If the ratio of the speed of boat 'Q' in still water to the speed of the current is the same as that for boat 'P,' with an upstream speed of boat 'Q' being 18 km/hr, determine the time taken by boat 'Q' to travel 144 km downstream.Solution
ATQ, Let the speed of the boat ‘P’ in still water and the speed of the current be ‘p’ km/hr and ‘q’ km/hr, respectively Therefore, downstream speed of boat ‘P’ = (p + q) km/hr Upstream speed of boat ‘P’ = (p – q) km/hr According to the question, {160/(p + q)} = {120/(p – q)} Or, 160p – 160q = 120p + 120q Or, 40p = 280q Or, p:q = 7:1 Therefore, ratio of speed of boat ‘Q’ in still water and the speed of the current = 7:1 Let the speed of the boat ‘Q’ in still water and the speed of the current be 7w km/hr and w km/hr, respectively According to the question, 7w – w = 18 Or, 6w = 18 Or, w = 3 Required time taken = {144/(7w + w)} = 144/24 = 6 hours
Which Indian author penned ‘Godaan’ (‘The Gift of Cow’)?
Match List – I with List – II and select the correct answer using the codes given below the lists:
Direct change of gas to solid without changing in to liquid is called _________.
Two lenses of powers +2.0 D and –2.5 D are combined to make an optical instrument. The combination will
Which freedom fighter is popularly known as Lok Nayak?
What is the current Cash Reserve Ratio (CRR) fixed by the Reserve Bank of India (RBI)?
In which state/UT is the Hemis festival celebrated?
Which of the following states is least likely to be among the top five contributors (installed renewable capacity) toward India’s renewable targets (i...
Who among the following elect(s) the presiding officer of the Vidhan Sabha in India?
Which chemical element of Group 18 of the periodic table is produced by the natural radioactive decay of uranium in soils and rocks?
