Question

If you treat both strands with an enzyme that recognizes the sequence GAATTC, record the number and size (invade pairs) of fragments from each sample of DNA

Answer 1

The enzyme would cut out the  GAATTC fragment in both strands, separating the DNA into 3 different fragments.

Strand 1 would have 3 fragments, one GAATTC (6 base pairs) one of 10 base pairs and one of 12 base pairs. (blue)
Strand 2: would have 3 fragments, one of GAATTC (6 base pairs) one of 18  base pairs  and one of 4 base pairs. (red)