Give an example of a relation or function from the world around you? Not good with real world problem thinking so can someone help me come up with an example?

Question

something · Answer

this is algebra btw

sooobored · Answer

A sweater costs x, the store is having a 25% off sale for all items, I have a $5 gift certificate, and i spent $34 including a tax of 7%

how much did the sweater initially cost?

something · Answer

not a school book example
like an actual example such as the higher the temperature, the more water that evaporates, but I cant use that example, i have to come up with a different one.

yanasidlinskiy · Answer

It has to be from a book?

something · Answer

no it cant be

sooobored · Answer

mine is totally a real life example

seratul · Answer

Yea, sooobored's example is pretty good.

sooobored · Answer

do you want something like this?

I have a wall with thickness of 1m, one side of the wall is isothermal at 300K the other side of the wall is at 400K, find the temperature profile at t=5 assuming k=10

something · Answer

no your not thinking about it right, your thinking mathematically

something · Answer

these were the two examples i was given but cant use: 
Change A, and B also changes. That's a relation. For instance, the higher the temperature gets, the more water evaporates. As inflation increases, real spending decreases.

something · Answer

you see how there are no numbers involved?

sooobored · Answer

ohhh, mathematic relations in real life

how about the gravitational constant?

sooobored · Answer

2 objects of a certain mass will have an attractive gravitational force towards each other, the larger the distance between them, the weaker the attractive force

yanasidlinskiy · Answer

This could be one as well: 
 Your age and your weight on your birthday each year.

sooobored · Answer

correlation does not imply causation

something · Answer

yeah but thats not constant @YanaSidlinskiy I dont think that would work

sooobored · Answer

linear relation?

something · Answer

i think you mass and gravitational pull example will work, thanks

sooobored · Answer

i mean, you could also do, the deeper you go underwater, the higher the pressure

something · Answer

that might work too

something · Answer

im glad you finally understood my question lol

sooobored · Answer

or the number of hours you sit infront of your computer related to the amount of power/electrical energy you use

sooobored · Answer

well on average

something · Answer

yeahhhhhhhhh....how about we stop there lol