Exams

Rocket works on the principle of conservation of momentum. The rockets gain momentum equal to the momentum of the gas expelled from the engine, but in the opposite direction.

Removing the contaminents if any in the water which causes harm to our health is involved in the purifying of water. 

This process involves chemicals. Chloramines, Hydrogen peroxide, Iodine are the chemicals which are used in purifying water.

Given number series follows a pattern that,

2

2 x 1.5 + 1 = 4

4 x 1.5 + 1 = 7 (not equal to 8)

7 x 1.5 + 1 = 11.5

11.5 x 1.5 + 1 = 18.25

18.25 x 1.5 + 1 = 28.375

Hence, the odd number in the given number series is 8.

$$\begin{gathered} ?2 = 2×78-21+8+49-148 \\ = 57 - 21 \\ =36 \\ => ? = ±6 \end{gathered}$$

The series follow the rule,

21 = 
77 = 92-4
165 = 132-4
285 = 172-4

5,9,13,17,21,(+4)...
In the same way next no. will be
212-4 = 441 - 4 = 437