For the following questions answer them individually
Prabhu travelled from his house a distance of 20kms to his friend's house. After some time he left his friends house and took a turn towards right and travelled 15 kms to reach a park. After resting for a while, he again started and turned to right and travelled 18 kms to reach a petrol bunk. From there he again turned right and covered a distance of 15 kms. How many km more he has to travel to reach home?