Please help me ASAP with shown steps

What sums are equal to 6/12? choose all answers that are correct a.6/12+6/12+6/12+6/12+6/12+6/12 b.2/12+1/12+1/12+2/12 c.5/12+1/12 d.1/12+1/12+1/12+3/12 plz : )

Out of $20$ creepy-crawly creatures in a room, $80\%$ are flies and $20\%$ are spiders. if $s\%$ of the total legs belong to spiders, what is $s$?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?