Questions

Each of the integers in the first set could be combined with any from the second set, giving a total of 4 x 5 = 20 possible pairs.

Of these the combinations that could give a sum of 23 are (5 + 18), and (9 + 14)

This means that the probability of getting a sum of 23 is 2/20 = 1/10

The absence of a nucleus is an adaptation of the red blood cell for its role. It allows the red bloodcell to contain more haemoglobin and, therefore, carry more oxygen moleculesLike red cells, platelets (thrombocytes) have no nucleus.Monocytes have a small spherical nucleus and has abundant dark staining condensed chromatin.There are 5 organelles found in a root hair cell. They are the: nucleus, cytoplasm, cell membrane, cell wall and vacuole.

The point or place of origin of an earthquake is called Focus. 

And,

The point where the seismic waves reach the surface is called as Epicenter.

Sound is a kind of energy created when something vibrates. When this vibration reaches an ear, it is translated into what we recognize as a sound. Sound vibration must travel through matter. Therefore, it can travel through air and water but not through vacuum.