Question
A boat covers 30 km downstream in 60 minutes. If the
ratio of the speed of the boat in still water to that of the speed of the stream is 8:4, respectively, then find the time taken by the boat to cover a distance of 15 km upstream.Solution
ATQ, Speed of the boat downstream = (30/60)×60 = 30 km/h Let the speed of the boat in still water = 8x km/h Speed of stream = 4x km/h Speed of the boat downstream = 8x+4x = 12x km/h 30 = 12x x = 2.5 Speed of the boat in still water = 8×2.5 = 20 km/h Speed of the stream = 4×2.5 = 10 km/h Speed of the boat upstream = 20−10 = 10 km/h Time taken by the boat to cover the distance of 15 km upstream = (15/10)×60 = 90 minutes
Which of the following type of plough is generally used for the breaking the hard pans?
When something in the landscape is repeated with a standard interval, it is called
Which of the following is an asexual reproduction?
Book entitled “Plowman’s Folly: A Second Look” was written by _____
Indian Institute of pulse research is located at
Founder of Nematology was:
First operational Indian Remote Sensing satellite IRS-1A was launched in the year
What will be the error degree of freedom for testing 5 varieties of wheat in Latin Square Design?
Among the following, which contributes maximum to the total millet produced in the country ?
Cross pollination range of gossypium hirsutum is _________ percent.