Exams

sedimentary features all are related to water deposited minerals and rocks.

Which of your choices has nothing to do with water is not a sedimwntary structure. Here in the given choices Magma emplacement is not a sedimentary structure.

The main constituent of biogas is methane (55-70%), CO2 (30-45%) and some traces of gases such as H2S and ammonia.

Biogas is produced under anaerobic conditions; the process is denominated as anaerobic digestion.

Antarctica is surrounded on all sides by water. The Indian, Pacific and Atlantic Oceans surround it on all sides. These three Oceans all meet at Antarctica. The three oceans are collectively called the Southern Ocean.

This is the area located south of 50° latitude.

Second is a bony protective covering for the first. Here pericardium protects Heart and Cranium protect Brain.

Hence, Heart : Pericardium :: Brain : Cranium.

Arithmatic mean = sum/members 

=> (1x1 + 2x2 + 3x3 + 4x4 + 5x5 + 6x6 + 7x7) / (1 + 2 + 3 + 4 + 5 + 6 + 7)

=> 140/28 = 5

Let Shilpa's present age is p years

According to question,

p = 4(x+4) – 4(x–4)

p = 4x+16 – 4x+16

p = 32

Shilpa's present age = 32 years

Rajeev is four years older than Shilpa

=> Shilpa's present age = Rajeev's age 4 years before.

=> Rajeev's age 4 years before = 32 years.