How to solve 3 simultaneous inequality equations

Question

p+e+n=100

n>2p

3p>4e

3e>n

Find p, e, and n

Answer 1

You have one equation; use it to solve for p; substitute into first inequality (now involves e & n only).

similarly substitute for p in second inequality.

 

You now have three inequalities involving just e & n.  Deal with these one at a time, shading above or below, as appropriate, a boundary line in the "e & n" coordinate system in each case. The solution is that region where all shadings overlap (intersect).