Conditions as stated in the question:
\(\frac{\frac{}{Monday} \leq \frac{}{Tuesday} \leq \frac{}{Wednesday} \leq \frac{}{Thursday} \leq \frac{}{Friday} \leq \frac{}{Saturday} \leq \frac{}{Sunday}}{\Sigma{76 Fish}}\)
(1)
Only 1 possible arrangement:
\(\frac{\frac{8}{Monday} \leq \frac{8}{Tuesday} \leq \frac{12}{Wednesday} \leq \frac{12}{Thursday} \leq \frac{12}{Friday} \leq \frac{12}{Saturday} \leq \frac{12}{Sunday}}{\Sigma{76 Fish}}\)
There is no other possible arrangment (go ahead and play around with it).
\(\longrightarrow SUFFICIENT\).
(2)
Let \(X\) represent the # of fish caught Tuesday. Then:
\(\frac{\frac{}{Monday} \leq \frac{X}{Tuesday} \leq \frac{X+4}{Wednesday} \leq \frac{}{Thursday} \leq \frac{}{Friday} \leq \frac{}{Saturday} \leq \frac{}{Sunday}}{\Sigma{76 Fish in Total}}\)
Let's figure out what the other values can be. Let's assign some variables.
\(\frac{\frac{A}{Monday} \leq \frac{X}{Tuesday} \leq \frac{X+4}{Wednesday} \leq \frac{B}{Thursday} \leq \frac{C}{Friday} \leq \frac{D}{Saturday} \leq \frac{E}{Sunday}}{\Sigma{76 Fish}}\)
We want:
\(A + X + (X + 4) + B + C + D + E = 76\)
\(0 \leq A \leq X \leq (X+4) \leq B \leq C \leq D \leq E \leq 12\)
What are the maximum possible values for each? 12. Substituting in we get:
\(0 \leq A \leq X \leq (X+4) \leq B \leq C \leq D \leq 12 \leq 12\)
\(E=12\)
\(0 \leq A \leq X \leq (X+4) \leq B \leq C \leq 12 \leq 12 \leq 12\)
\(D=12\)
\(E=12\)
\(0 \leq A \leq X \leq (X+4) \leq B \leq 12 \leq 12 \leq 12 \leq 12\)
\(C=12\)
\(D=12\)
\(E=12\)
\(0 \leq A \leq X \leq (X+4) \leq 12 \leq 12 \leq 12 \leq 12 \leq 12\)
\(B=12\)
\(C=12\)
\(D=12\)
\(E=12\)
\(0 \leq A \leq X \leq (X+4) \leq 12 \leq 12 \leq 12 \leq 12 \leq 12\)
\(X+4=12 \longrightarrow X=8\)
\(B=12\)
\(C=12\)
\(D=12\)
\(E=12\)
\(0 \leq A \leq 8 \leq 12 \leq 12 \leq 12 \leq 12 \leq 12 \leq 12\)
\(X=8\)
\(B=12\)
\(C=12\)
\(D=12\)
\(E=12\)
\(0 \leq 8 \leq 8 \leq 12 \leq 12 \leq 12 \leq 12 \leq 12 \leq 12\)
\(A=8\)
\(X=8\)
\(B=12\)
\(C=12\)
\(D=12\)
\(E=12\)
\(A + X + (X + 4) + B + C + D + E = 8 + 8 + (8+4) + 12 + 12 + 12 + 12 = 8 + 8 + 60 = 76\)
So there is only one possible arrangement possible, because if we take anything less than the maximum, the days won't sum to 76 as required in the question. This is also the same arrangement as in (1).
\(\frac{\frac{8}{Monday} \leq \frac{8}{Tuesday} \leq \frac{12}{Wednesday} \leq \frac{12}{Thursday} \leq \frac{12}{Friday} \leq \frac{12}{Saturday} \leq \frac{12}{Sunday}}{\Sigma{76 Fish}}\)
\(\longrightarrow SUFFICIENT\)
Final Answer, \(D\).
\(\surd\)