How many blades of grass are there in your random sample area?

Let's assume there are 10 blades of grass per square centimeter. This means there are 100.000 blades of grass per square meter and 100.000.000.000 blades of grass per square kilometer.

The surface area of earth is 5.1 * 108 km2

The surface of earth is roughly 70.8% water (Ibid), which means that 29.2% is land. Of these 29.2% approximately 20% is grass

This means the surface area of all grass areas combined is:

Area_of_grass = 5.1 * 108 km2 x 29.2 % x 20 % = 29 million km2

Hence,

blades = 1011 blades of grass / km2 * 29 million km2 = 3 * 1018 blades of grass

This is approximately 418 million blades of grass per person alive.

the answer to your question is tooth decay.

evidence and logical support is essential for a scientist to do in order to maintain credibility. this is because no one can believe without any logic and without any evidence.hence a scientist can maintain credibility by proving himself and by answering logically so experiments prove very beneficial. logical hypothesis give conclusion which is acceptable. therefore, there are two main factors to maintain credibility by a scientist is evidence and logical support.