The sporting goods store where the campers purchased their backpacks can sell 90 packs for $200 each. For every $10 decrease in price, 5 more packs will be sold. The
number of backpacks that must be sold to generate revenues of $12 000 is:

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?