statement 1 gives you the slope of line l is 3 times its y-intercept. Knowing this fact on it's own is insufficient to finding the slope of the line, as we have no reference point. Furthermore, if line l crosses above or below the x-axis that will affect the slope making it positive or negative, depending on the reference point, which we do not have. Therefore, statement 1 is insufficient.
statement 2 gives the x-intercept but gives no hint as to how the line proceeds through that point. Going through (-1/3,0) the line could cross the y-intercept anywhere from +infinity to -infinity. Therefore insufficient.
Statements 1 and 2 taken together look like they may solve the answer. From statement 2 we know the x intercept (-1/3,0). However, does line l pass through th y-intercept at (0, 1) or (0, -1)? Both of these points would fulfill statements 1 and 2 together, there for statements 1 and 2 taken together are NOT sufficient. (E)