What is the number in standard form? 4.9×10^8

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.

Azul has 4 green picks and no orange picks. you add orange picks so that there are 2 orange picks for every 1 green pick. how many picks are there now.

Factor this polynomial completely. x^2-8x+12