Ratio of distance covered by boat in upstream to downstream is 4:3. Time taken in downstream and upstream is 2hr and 4 hr respectively. If speed of boat in still water is 15 km/hr then find speed of stream.
Let distance covered by boat in upstream and downstream be 4x and 3x km respectively. And speed of stream be y km/hr. ATQ, => 4x/(15 – y) = 4 => 4x + 4y = 60 ------ (i) => 3x/(15 + y) = 2 => 3x – 2y = 30 ------ (ii) Solving (i) and (ii), we get => x = 12, y = 3 km/hr Speed of stream = 3km/hr
Propodeum is found in the insect belonging to the sub-order:
Insects, which feed on one type of food, are called _______.
Which of the following pair is not correct?
………………….. is associated to achieve the goal of Sweet Revolution in country
The silk fibres are held together in cocoon by a substance known as
Which of the following are the characteristic features of an Insect?
Which of the following is called the resting and inactive stage in the insect life cycle?
Shellac is secreted by
Apis mellifera is also known as
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