Question
A boat takes 8 hours to travel 240 km upstream. If the
speed of the boat in still water is 40 km/h, how much time will it take for the boat to travel 120 km downstream?Solution
Let the speed of the stream be x km/hr. So, upstream speed = (40 – x) km/hr According to the question, 240/(40 – x) = 8 x = 10 km/hr So, downstream speed = 40 + x = 40 + 10 = 50 km/hr Required time taken to cover the distance = 120/50 = 2.4 hours
In humans, fertilization usually occurs in the:
A particle starts from rest and moves with uniform acceleration for 24 seconds. Let the distances covered during the first 8 seconds, the next 8 seconds...
Which of the following is/are true about the human heart?
I. The heart has valves to ensure blood does not flow backwards when the atria or ventr...
What is the pH level of pure water?
Which of the following is an example of a chemical change?
Which of the following vitamin helps during blood clotting?
Which of the following mixture is burnt to produce very high temperatures and are used for cutting metals and for
welding?
Which one of the following crops enriches nitrogen content in the soil?
Which of the following is not a physical change?
According to Newton’s second law of motion, the acceleration of an object is directly proportional to the
Relevant for Exams:
