Question

"would you post this letter when you go out/" he said

Answer 1

Answer:

He asked me if I can post the letter when I go out.

Explanation:

While changing the sentence, I converted would into can because in the question,it is asked if I can do that work.So,probably "can" can also be used.

We also change said to "asked" and change the tense.

The most important point to keep in mind is to make a sentence which does not change the meaning of the previous sentence.