microeconomics Q

plz solve this in 5 min!!

The above table gives some of Tammy's total and marginal utilities from comedy videos. Which of the following statements is true? Tammy's total utility from five comedy videos is 780 . None of the above answers are correct. Tammy's marginal utility from the first comedy video is less than her marginal utility from the third comedy video. Tammy's marginal utility from the third comedy video is equal to 580/3