Answer: Joe is 2 years old
Explanation:
Let x represent the age of Joe.
Sally is 1 year older than 3 times the age of Joe. It means that the age of Sally is
3x + 1
Chirs is 5 years younger than 6 times the age of Joe. It means that the age of Chris is
6x - 5
If sally and Chris are the same age, it means that
6x - 5 = 3x + 1
6x - 3x = 1 + 5
3x = 6
x = 6/3
x = 2 years