Show how you got from 135 to to 175 counting by fives

Isuck at math ; ^; m a student solved this problem and said the answer is 3 feet. chase had a roll of ribbon that contained 7 7/8  feet of ribbon. he cut off one piece that was 3 5/8  feet long and another piece that was 1 1/4  feet from the roll. how much ribbon was left on the roll? is the student's answer reasonable? yes, the answer is reasonable. no, the answer is not reasonable. it should be about 2 feet. no, the answer is not reasonable. it should be about 13 feet. no, the answer is not reasonable. it should be about 4 feet.

Mrs.sling bought a pound of green beans for $1.80. how much will mrs.tennison pay for 3 1/2 pounds of green beans?

Is experimental probibilty the same as the observed frequency in math? i need the answer asap!