How do you find the answer to a missing number in an regulation 415,418,423,427,430?

for me what is finding a good play list and going out because i can not lay down and relax so i usually go to a coffee shop. i also use the gum trick and this actually works. another advice is highlighting subjects it really does me remember certain things

step-by-step explanation:

it's undefined because anything multiplied by 0 is 0. that said, 7 days is 168 hours