We know that 7/10 of the cookies are chocolate chip, so that means there are 3/10 of the cookies left.
We now want to find what 3/4 of 3/10 is.
We can do this by multiplying both fractions
3/4x3/10 (we just multiply across) to get 9/40.
We cannot simplify this answer, so our final answer is 9/40 of the cookies are sugar cookies.
