"a majority, but not all, of the garden's sycamores are older than any of its maples."
Q1: S-most-OTM OTM-some-S
"All the garden's maples are older than any of its dogwoods.
P2: M ==> OTD not OTD ==> not M
This one is a bit tricky because we don't really need our diagrams to come up with the answer choice.
The correct answer choice is (E): "some sycamores are not as old as the youngest tulip trees."
So, since we know that some sycamores, BUT NOT ALL are older than maples, then that means that at least one sycamore is younger or the same age as the maples. And since all tulip trees are older than any maples, then there is at least one sycamore that is not as old as any of the tulip trees, i.e. answer choice (E): "Some sycamores are not as old as the youngest tulip trees."
Hope that clears things up! Please let us know if you have any other questions.