No. 6 is 50 - 50 x 0 = ? Here you should do multiplication first according to PEMDAS. 50 x 0 = 0 so the answer is 50. The given answer is correct. Hope this helps.
When I did this quiz, I was new to PEMDAS because we were not taught it. I had seen in another quiz that left-to-right referred to the order they were presented in PEMDAS which meant multiply came before divide. I know better now. Sorry for the confusion.