Since pre increment and pre decrement have right associativity. Pre increment and decrement operator have more precedence than multiplication operator.
In Y=(++x)*(++x)*(++x), evaluation is done as follows:
Evaluation order is separate from the associativity order. Associativity only specifies the operands for the operators and when and how the operands are evaluated is independent of it.
Thanks @Arjun sir. I understood the concept.