Questions

The F1, F2 to F12 keys that are found on the top row of most computer keyboards are called as Function Keys. Unless you've witnessed the evolution of computers from their early days, you probably don't know why they were invented and for what.
Function keys were used by various computer programs to fulfill various functions.

F12 - It is used by many web browsers to open the developer tools.

Weight is mass x g. Since mass is constant and g is only 16thof that on the earth. The weight on the moon is only 16th of that on the earth. 

Therefore 2N i.e (b) is the answer.

Sound intensity is measured in decibels(db). Sound pollution above 120 db becomes more hazardous and have adverse affects on human life. 

If you want bonus points, make sure you address each side of this tricky two-part question. 

The first part is addressing how you make sure you greet each and every customer who enters the store, giving them personal attention.  

The second part is how you would actually greet them – what would you say to them? Would you alert them of your newest products, ask if they’re looking for anything in particular or need guidance while shopping, or alert them to who they can reach out to if they require any assistance in various departments?