A man can go on a motor boat with a speed of 15 km/hour in still water to a certain upstream point and come back to the starting point in a river which flows at a speed of 5km/hour. Find the average speed of motor boat for total journey?
Let, the speed of boat be b km/hour and speed of current be s km/hour Average speed = 2xy/(x+y) (here, x is speed of downstream and y is speed of upstream) = (2 (b+s)(b-s))/((b+s+b-s)) = (b2 - s2)/b = (225 - 25)/15 = 200/15 = (40/3) km/hour Alternate Method :- 
Average speed = (Total distance covered)/(total time taken) = (2×60)/9 = 120 /9 = 40/3 kmph
Trogoderma granarium is important stored grain pest which is commonly known as:
Which one of the following is the most productive soil in India?
Any purchaser/person can send their sample to food analyst for getting analyzed provided thatÂ
A combination of erosion permitting and resistive crops in alternate rows are constructed perpendicular to the direction of wind and water flow, to pre...
Storage temperature mainly prefer for frozen foods is/are
The use of tensiometer is confined up to metric potential of!
Recently iron rich red rice is exported from which state of india to USA?
Papaya ringspot disease is spread through:
In living plant cell conversion of Pyruvic acid into COâ‚‚ and energy is called
The 3rd day of the 5 days training program for designated Officer focuses on:
