A fishing boat receives $1.50 for each tuna it brings back to port and

Official Explanation

We look at this question and we see algebra. This is a classic word problem in which algebraic statements have been expressed in English. Most likely, we will use the n variables, n equations here. I.e., we are missing the number of mackerels and the number of tuna. If we can form two distinct equations with those variables, we'll be able to solve for both variables. On to the statements, which we'll look at separately. The first statement gives

T = 2M - 5

Which is a good equation, but we only have one total. So the first statement is insufficient. The second statement gives me

1.5T + 1.8M = 2960

Which logically has the same problem--we have only one equation, total. However, if we combine the statements, we have two equations for two variables, so the n variables, n equations rule is satisfied, and we'll be able to solve for both T and M. So the statements are sufficient together. In practice this can all be done without writing the equations, so long as you are certain that the equations are distinct and they are linear equations.

The correct answer is (C).