On a multiple choice test with 21 questions, each question has four possible answers, one of which is correct. for students who guess at all answers, find the standard deviation for the number of correct answers

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

The appalachian trail is a hiking trail that passes through the appalachian mountains. three members of a teen hiking group hiked a section of the trail. the hikers stopped at a rest area and equally shared 3 4 gallon of water. how much water did each person get?

The graph of h(x)= |x-10| +6 is shown. on which interval is this graph increasing