Questions

The payback period is how long it takes to recoup your investment. In this example, the cost was $4,000,000 and the savings was $800,000 per year. $4,000,000/$800,000 = 5. Therefore, Answer A, B and D are incorrect.

Yaounde is the capital of Cameroon

Viruses are responsible for some of the most dangerous and deadly diseases including influenza, ebola, rabies and smallpox.

Despite their potential to kill, these potent pathogens are in fact considered to be non-living.

Reasons:

1. Viruses don't have any cells, like living organisms do. They have protein coats but no organelles or other cellular machinery. Just a little DNA packet.

2. Viruses can't produce new proteins, DNA, or RNA and therefore are unable to reproduce on their own. They need infected cells' machinery to make all of these and produce new virons.

3. Viruses have no metabolic activity. They don't use or convert energy and have no ongoing interior processes. They're basically just inert structures until they impact a potential host cell.

The earliest historic evidences of use of metal are of Chalcolithic Age or Stone-Copper Age, which covered the period from 1800 - 800 BC. This period was by the use of Copper as well as stone.

Hence, the first metal to be used in India is Copper.