HELP PLEASE!! What are the answers, say the answers to the blanks and if you can please try to explain it please i failed algebra 3 times and i really need help

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?

Which fraction is equal to 1hole and 2/5? a.3/5 b.75 c.57 d.73

Ingredient c: 1/4 cup for 2/3 serving or ingredient d: 1/3 cup for 3/4 serving which unit rate is smaller