Geometry question and inequality

First one answered here : https://web2.0calc.com/questions/help_9075

Oh okay XD i can't seem to find this stuff :P

Here's the way I interpret the second question

Let your truck be capable  of carrying  x  lbs

Let  the total number of pounds that your neighbor can carry in 4 identical trucks  =  y

So each of your neighbor's trucks can carry  y / 4   lbs

"My truck can carry at least 800 pounds more than each of her trucks"  translates to

x ≥  800 + y / 4

And 

"...but no more than one-third what all four of her trucks combined can carry"  translates to

x ≤  y/3

Look at the intersection point of these two inequalities :  https://www.desmos.com/calculator/xggshl0aos

Your truck can carry  3200 lbs  .....

Your neighbor's trucks can carry  9600 lbs

So  each of her trucks  can carry  9600/ 4  = 2400 lbs

And your truck carries at least 800 lbs more than each of her trucks [ 3200 - 2400 ]

Plus  your truck can carry no more than 1/3  of what all 4 of her trucks can carry.....9600/3  = 3200 lbs

Oh wow! I never thought of it as an intersection question! That helps alot! oh Im acidentally using a guest...