Strata and Relative Time homework

Youngest:

I think 3 is the youngest because intrusions are younger than the layers of rock they cut through and it cuts through the top layer of rock which is the youngest.

I think 1 is the second youngest because it is the top layer of rock, which according to the laws of superposition means it is the youngest.

I think 6 is the next youngest because it is second closest to the top of the rock formation.

Then I think it is 5 because it is next closest to the top.

Then it is 4 because it is under five but not quite at the bottom.

Last is 2 because it reaches the bottom of the rock formation which makes it the oldest.