Statement 1 tells us the percentage of women that have red hair, but does not provide a way to determine what percentage of the entire group is made up of women or red haired women.

Insufficient.

Statement 2 tells us nothing about red haired women.

Insufficient.

Combining the statements we still have no way to determine what percentage of the entire group is made up of women or women with red hair.

So the correct answer is E.

We can also do it algebraically.

We've got w and m men. Combining the statements, we have .05w + .10m redheads.

So that % of redheads = (.05w + .1m) / (w + m). But we can't simplify this to an number: the variables don't cancel.