Questions

The given letter equation implies that, 

7 C in the R = 7 Colours in a Rainbow.

The elements in the same column will have similar properties. Beryllium is the group II element. Group II elements are magnesium, calcium, strontium, barium and radium. Hence, these show the similar prperties.

The hertz (Hz) is defined as one cycle per second and is a SI unit of frequency. Here kilohertz is also a unit of frequency of waves and is defined as 1000 cycles per second. Radio waves are measured in kilohertz (KHz).

An object at rest may have Potential energy.

In the given puzzle the logic is

2 x 1 + 1 = 2 + 1 = 3

3 x 2 + 2 = 6 + 2 = 8

4 x 3 + 3 = 12 + 3 = 15

5 x 4 + 4 = 20 + 4 = 24

6 x 5 + 5 = 30 + 5 = 35

Similarly,

7 x 6 + 6 = 42 + 6 = 48

7 = 48.

Indian Cricket team off-spin specialist Ravichandran Ashwin has become the fastest cricketer to take 250 wickets in the Test matches. Ashwin surpassed Australian fast bowler Dennis Keith Lillee to reach the milestone of 250 Test wicket. Thus Ravichandran Ashwin has become the sixth Indian bowler to reach 250 test wickets.

Jean-Jacques Rousseau (1712–1778), in his influential 1762 treatise The Social Contract, outlined a different version of social contract theory, as the foundations of political rights based on unlimited popular sovereignty.