Explanation
The given sentence is in Present Indefinite Tense.
Why do you waste your money means تم اپنا پیسہ کیوں ضائع کرتے ہو؟
Waste is a verb here.
Wasted is the second and third form of Waste.
Present Indefinite Tense
Active Voice: Subject + Verb + Object
Passive Voice: Object + is/am/are+ third form of a verb + by + subject.