(Help me please)
The imagenIs the question´

How much dextrose 70% must be mixed with dextrose 5% to prepare 1,000 ml of dextrose 20%?

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.

Me complete this proof! prove that a quadrilateral is a square. me with the steps for this proof.