i have a question, about single/double quotations Options

[Jinny]

well i have a grammar test tomorrow.. so i guess i have to get help by tonight.
this might be reaalllyy easy but i don't listen at all in class. and yeaahh..

okay. pretend the sentence is: (i made these sentences up)

Mary said, "I love the song 'Hello'."
would the period go between the single+double quotation marks, would the period go after the double quotation marks, or would the period go inside the single quotation marks?

also if the sentence was:
"I love the song 'Hello'," Mary said.
would the comma go between the double+single quotation marks, inside the single quotation, or after the double quotation marks?

AGAIN. what if the sentence was:
"Did Mr. Smith say, 'Your reports are due tomorrow'?", asked Mary.
I'm so confused with that one. Would the comma go after the word "say"? would the question mark go inside the single quotation marks? or after the double quotation? and would the comma go after the double quotation marks?

i probably don't make any sense but please...?