Aidan walked from home to his friend's house, which is 900 m away, in 15 minutes. He stayed at his friend's house for 30 minutes, and then walked back home in 10 minutes. The problem asks to find the value of $d$ which represents the distance from Aidan's home to his friend's house.

1. Problem Description

Aidan walked from home to his friend's house, which is 900 m away, in 15 minutes. He stayed at his friend's house for 30 minutes, and then walked back home in 10 minutes. The problem asks to find the value of $d$ which represents the distance from Aidan's home to his friend's house.

2. Solution Steps

The problem states that the friend's house is 900 m away from Aidan's home. From the graph, $d$ represents the distance from Aidan's home to his friend's house.

Therefore, $d$ = 900 m.

3. Final Answer

$d = 900$ m