The blended price of a mix per kg can be rewritten as (100q+80p+50r)/1000 = 0.1q+0.08p+0.05r, assuming q, p, r are all measured in grams. For simplicity of calculation, we can use the blended price per 1000kg which is the same as the original formula 100q+80p+50r.
Statement 1:
The price of the mixture of type I & III would be anything between 50 (where type I barely exists) and 100 (where type III barely exists). Without information about type II, we can only know that the overall mix price is also between 50 and 100 but the more there is type II, the closer it will be to 80. No definitive comparison can be drawn between A & B.
INSUFFICIENT.
Statement 2:
Knowing type I is 40% and 20% in A and B, respectively, we can write the overall mix price as:
A: 100*40%+80*(100%-40%-type III% in A)+50*(type III% in A)
B: 100*20%+80*(100%-20%-type III% in B)+50*(type III% in B)
A-B gives (40+48-30*type III% in A)-(20+64-30*type III% in B) = 4+30*(B_III% - A_III%). Since we don't know the relationship between B_III% - A_III%, the end outcome could be either positive or negative.
To illustrate, for A-B<0 (i.e. B is more expensive), 4+30*(B_III% - A_III%)<0 >> B_III% - A_III%<-13%; for A-B=0, B_III% - A_III%=-13%; for A-B>0, B_III% - A_III%>-13%. That is, given there is already proportionally more costlier type I leaves in A, there needs to be materially less type III in the mix for B to become more expensive overall than A, vice versa, with a breakeven threshold of 13% less.
INSUFFICIENT.
Combining both statements, we know A_I% is definitely greater than B_I%, and that A_III% is greater than B_III%. We can only conclude A & B's relationship based on the size of the percentage difference of type III leaves, according to the threshold identified as part of our analysis of Statement 2.
INSUFFICIENT.