I am completely stuck on this, please explain clearly.

Many thanks

In this question x * y means (x+2y)/3 if x < y, and (2x + y)/3 if x is larger or equal to y.

a) Find the value of

i) 5 * 8

ii) 8 * 5

b) Solve

iii) x * 7 = 8

iv) x * (x-1) = 4 2/3 (that's 4 followed by 2/3 as a fraction)

c) In terms of p and q, find the possible values of (p * q) *p, explaining carefully how you choose which calculations to make.