Questions

Africa is the second largest continent both by popolation and area wise. Asia being first by both popolation and area wise.

In a first, China is planning to send mini-ecosystems — containing potato seeds and silkworm eggs — to the Moon next year, in an attempt to study how the organisms develop on the lunar surface. The 3-kilogramme mini-ecosystem, developed by research teams led by Chongqing University in China, will be sent to the Moon by the Chang’e 4 scheduled to be launched in 2018, authorities announced at the Global Space Exploration Conference. An 18-centimetre-tall cylinder will carry potato seeds and silkworm eggs to be incubated.

Allotropes are the different physical forms of an element. Here in the given options, diamond and graphite are the pair of allotropes of carbon.

Some more examples are Molecular oxygen and ozone are pair of allotropes, Black and red phosphorous are also pairs of allotropes.

Given two trains of length = 180 mts + 180 mts 

The distance is = Length of trains = 360 mts 

Speed = 58 - 50 = 8 kmph x 5/18 m/s

Then, Time = dis/speed = (360x18) / (8x5) = 162 sec.