Yes, it is possible to use both tenses. But you should use "throw" it out, not "through" which has a different meaning.

The first question of using DID, should be used informally and HAVE should be used formally. It would come across fairly rude to say to someone that you don't know, why did you do this or that! Also, it's..now we have to THROW the rest of it out! There are some similar words that might sound the same but are very different in meaning, you might want to look these up.. Through Thought Threw Thorough Thaw Two Torn

1. "Why did you cook so much food for dinner? Now we have to throw the rest of it out." 2. "Why have you cooked so much food for dinner? Now we have to throw the rest of it out." both correct; 1. mainly American usage 2. mainly British usage

I would say number 1. Why did you cook so much food for dinner? Now, we have to throw the rest of it out. Confusion regarding the use of ‘throw and ‘through’ arises from the fact that they are homophones, ie, they are pronounced the same way. To throw out is to dispose of and The sunlight coming through the window woke me up. Jean