Answer:
Steam boat = 20 Knots , Yacht = 40 Knots
Explanation:
Let the distance travelled by both the boats be x
Case 1: Steamboat
Speed

Case 2 : Yacht


Also given that speed of yacht is 20 more than that of steamboat

Hence



Hence the distance traveled is 100 naut miles
Hence
Speed of Steam boat =
= 20 Knots
Speed of Yacht =
= 40 Knots