Questions

From the assumption and trial and error method,

last three digits sum must leave the same digit as the answer. It is possible only if the answer must be units digit number leaving tens digit as carry.

And the possible 3rd digit is 5. Since 5 + 5 + 5 = 15 

Now, 2nd step is  1 + x + x + x = 5

=> 3x = 4

It is possible with x = 8. 8 + 8 + 8 + 1 = 25 leaving 2 as carry. 

Now, 3rd step is 2 + x + x + x = 5 => x = 1

Hence, the three dgits are 1, 8, 5.

185 + 185 + 185 = 555. 

Epiglottis is that prevents food from entering the windpipe. 

It is a cartilageous flap that flaps opens and closes when swallowing. When you swallow, the epiglottis flattens backward to cover the entrance to your larynx and prevent food from entering the lungs and windpipe. The epiglottis returns to its usual position after swallowing.

The inside of the bulb being a vacuum, the outside air rushes in when the bulb is broken. The vibrations of the rushing air molecules produce the sound.

Now a days, printers we are using are called as laser printers. The speed of a laser printer is measured in PPM i.e, Pages Per Minute. 

Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back and forth over a negatively charged cylinder called a "drum" to define a differentially charged image.

Compared to inkjet printers which use ink for printing laser printers are more expensive as they use toner which lasts for long.

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.