A music store buys instruments and then sells them for 30% more than they paid. During a 20% off sale, the store offers a clarinet for $93.60. How much did the store pay for the clarinet?

When taking a 27 question multiple choice test, where each question has five possible answers, it would be unusual to get  or more questions correct by guessing alone. Use the Range Rule of Thumb for Unusual Values to answer this question. Give your answer above as a whole number.

How many handshakes are required for a group of 8 people to shake everyone's hand?

d²y (1) +6dy +8y= u(1) di dt where y(0) = 0; y'(0) = 1.