Questions

Ans.  Suppose the speed of boat in still water is x km/h and speed of stream is y km/h

Speedof boat in downstream = (x + y) km/h x+ y = 32 …(i) 

Speed of boat in upstream = (x – y) km/h

x – y = 28 …(ii)

Add. Eqs. (i) and (ii), we get 2x = 60

x = 30 km/h

Core of earth is also known as Barysphere.

The first wholly artificial gene was synthesized by Har Gobind Khorana.

Beta is the measurement of the systematic risk of the market.

The study of volcanoes, lava, magma, and related geological, geophysical and geochemical phenomenas is called Volcanology.

Our atmosphere is made up of

78% Nitrogen,

21% Oxygen and

1% all other gases like argon, carbon dioxide, neon, and helium.

So, Nitrogen makes up the majority of our atmosphere.

Secondary succession means in an ecosystem renewal of itself after all or a portion has been destroyed.

After a forest fire, the whole forest had destroyed but after that again renewal of that forest is also an example of secondary succession.