Answer:
#3 you are correct.
#4 you are correct.
Step-by-step explanation:
#3) Similar triangles have common ratio for all 3 sides.
AD=24 DB=27 EB=18
DB/AB = EB/CB
DB CB = EB AB
DB (CE+EB) = EB (AD+DB)
27(CE+18)=18(24+27)
CE=18(24+27)/27 - 18 = 16
#4) If the triangles are similar then their third sides are parallel
AD=15 DB=12 so AB=27
AE=10 EC=8 so AC=18
AC/EC = 18/10 = 9/4
AB/DB = 27/12 = 9/4
The triangles are similar, so BC || DE
