Explanation:
Ann posted 1/3 of the fliers last week, which means she posted:
1/3 x 48 = 16 fliers
This means that she has 48 - 16 = 32 fliers left to post.
This week, Ann posted 1/4 of the remaining fliers, which means she posted:
1/4 x 32 = 8 fliers
So she has 32 - 8 = 24 fliers still to post. Therefore, Ann has still not posted 24 fliers.