Speeds of two trains = 30 kmph and 58 kmph

=> Relative speed = 58 - 30 = 28 kmph = 28 x 5/18 m/s = 70/9 m/s

Given a man takes time to cross length of faster train = 18 sec

Now, required Length of faster train = speed x time = 70/9  x  18 = 140 mts.

Let the distance in one direction = k kms

Speed in still water = 4.5 kmph

Speed of river = 1.5

Hence, speed in upstream = 4.5 - 1.5 = 3 kmph

Speed in downstream = 4.5 + 1.5 = 6 kmph

Time taken by Rajesh to row upwards = k/3 hrs

Time taken by Rajesh to row downwards = k/6 hrs

Now, required Average speed =$$\begin{gathered} Total distanceTotal speed = 2kk3 + k6 \\ = 2k x 186k + 3k = 4 kmph \end{gathered}$$ 

Therefore, the average speed of the whole journey = 4kmph.

Culture is the social behavior and norms found in human societies. The 7 main elements that make up culture are ::

1. Social organization
- the family patterns and social classes of a culture.

2. Customs and traditions
- way people act, wear, what they eat, and their laws.

3. Language
- communication by word of mouth.

4. Religion
- a system of beliefs that answers questions about the meaning of life.

5. Art and literature
- ways the people entertain themselves. There stories they tell and how they dance. Its also the music they listen to and there artwork.

6. Forms of government
- the people or group(s) that control the people and provide/ enforce the laws.

7. Economic systems
- the method used by a society to produce and distribute goods and services.

In the early 1950s two scientists, Rosalind Franklin and Maurice Wilkins, studied DNA using x-rays. Franklin produced an x-ray photograph that allowed two other researchers, James Watson and Francis Crick to work out the 3D structure of DNA. The structure of DNA was found to be a double helix.

Apply the RM process to situations where serious injury might occur is not a RM (Risk Management) principle.

Risk Management :: A decision-making process for managing day-to-day schedules when there are conflicts.

Office salaries expense would not come under a selling expense.

Hence, soil erosion on hillslopes can be checked by Terrace cultivation.

A cytoskeleton is the frame that gives shape to a cell. And also it offers support, and facilitates movement through three main components:

microfilaments,

intermediate filaments, and

microtubules.

The cytoskeleton helps the cell move in its environment and controls the movement of all of the cell's interior workings.