Mixtures and Motion

Don wants to invest $70,000 to earn $5900 per year. He can invest in B-rated bonds paying 11% per year or in a CD paying 7% per year. How much money should be invested in the CD?

The manager of a coffee shop has one type of coffee that sells for $7 per pound and another type that sells for $14 per pound. The manager wishes to mix 40 pounds of the $14 coffee to get a mixture that will sell for $12 per pound. How many pounds of the $7 coffee should be used?

An airplane flies 450 miles with the wind and 300 against the wind in the same length of time. If the speed of the wind is 20 mph, what is the speed of the airplane in still air?

A chemist needs 100 mL of a 33% solution, but has only 19% and 39% solutions available. Find how many mL of the 19% solution should be used to get the desired solution.

Five friends drove at an average rate of 60 mph to a weekend retreat. On the way home, they took the same route, but averaged 75 mph. What was the distance between home and the retreat if the round trip took 10 hours? Round to the nearest mile.

How much pure acid should be mixed with 5 gallons of a 50% acid solution in order to get an 80% acid solution? Round to the nearest tenth.

During a hurricane evacuation a family traveled 200 miles west. For part of the trip they averaged 60 mph, but as the congestion got bad, they had to slow to 10 mph. If the total time of travel was 9 hours, how many miles did they drive at the reduced speed?

A freight train leaves a station traveling at 32 km/h. Two hours later, a passenger train leaves the same station traveling in the same direction at 52 km/h. How long does it take the passenger train to catch up to the freight train? Round to the nearest tenth.