Questions

A resource is a source or supply from which a benefit is produced. Resources can be broadly classified upon their availability they are renewable and non renewable resources.

Renewable Resources :: A resource that can be replenished after use are known as Renewable resources.

Examples :: Sunlight, Water, biomass,...

Non renewable Resources :: A resource that, once used, is no longer available are known as Non renewable Resources. 

Example :: Coal, fossil fuels, natural gas,...

Sunlight is the both renewable and inexpensive resource from the given options.

Microwaves are high-frequency signals in the 300 MHz to 300 GHz range. This is in contrast to radio signals, which are typically broadcast in all directions. Radio signals operate in the 3 Hz to 300 MHz range.

Microwave signals are used for both satellite and ground-based communications.

Here the given Number Puzzle follows a pattern that, Sum of the numbers on the corners on the two squares is same and is equal to 54.

i.e,

13 + 15 + 14 + 12 = 54 

and

8 + 22 + 9 + 15 = 54