3) Every year Sully buys 130 red pens for grading at the beginning of the year. He figures that the number of pens decreases exponentially at about 9% each week. When he only has 10 left he goes and buys more.
a) Set up an exponential equation for the given situation.
b) Rewrite the equation as a logarithm.
c) Expand your logarithm using Properties of Logarithms.
d) How many weeks until Mr. Sullivan needs to buy more pens?

What is the answer to this problem 7 * 5/6

Asays "we are both knaves" and b says nothing. exercises 24–31 relate to inhabitants of an island on which there are three kinds of people: knights who always tell the truth, knaves who always lie, and spies (called normals by smullyan [sm78]) who can either lie or tell the truth. you encounter three people, a, b, and c. you know one of these people is a knight, one is a knave, and one is a spy. each of the three people knows the type of person each of other two is. for each of these situations, if possible, determine whether there is a unique solution and determine who the knave, knight, and spy are. when there is no unique solution, list all possible solutions or state that there are no solutions. 24. a says "c is the knave," b says, "a is the knight," and c says "i am the spy."

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.