#1. An herbalist has 25 oz of herbs costing $4 per ounce. How many ounces of herbs costing $1 per ounce should be mixed with these 25 oz of herbs to produce a mixture costing $2.50 per ounce? #2.The manager of a farmer's market has 500 lb of grain that costs $1.70 per pound. How many pounds of meal costing $0.80 per pound should be mixed with the 500 lb of grain to produce a mixture that costs $1.40 per pound?
#3. Find the cost per pound of a "house blend" of coffee that is made from 10 lb of Central American coffee that costs $9 per pound and 40 lb of South American coffee that costs $4.50 per pound.
#4.Two cars start at the same time, but travel in opposite directions. One car's average speed is 30 miles per hour (mph). At the end of 4 hours, the two cars are 280 miles apart. Find the average speed in mph of the other car. (Enter an exact number.)