1. a pharmacist has 20 L of a 10% drug solution. How many liters of 5% solution must be added to get a mixture that is 8%? GIVEN liters of solution : 20, liters of pure drug 20(.10) Rate: .05, .08
2. How many gallons of a 12% indicator solution must be mixed with a 20% indicator solution to get 10 gal of a 14% solution?
3. crystal wants to buy two kinds of beans: arabian mocha and Colombian decaf. if she wants twice as much mocha as Colombian, how much of each can she buy for a total of 87.50?
4.a driver averaged 53 mph and took 10 hr to travel from Memphis to chicago. what is the dstance between Memphis and Chicago?
5. atlanta and cincinnati are 440 mi apart. john leaves Cincinnati driving toward atlanta at an avg speed of 60 mph. pat leaves Atlanta at the same time, driving toward cincinnati in her antique auto, averaging 28 mph. how long will it take them to meet?
I really need help on how to solve these. please show all the steps. 10 POINTS!!! 
thanksssss in advance(ten points not only to answers, but work shown)