#1. How many three-letter words can be made from using the letters of the word "GUARD" (no repeats)
Then notation:

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. how many hours after the truck's departure will the two meet?

Identify the number as a rational or irrational.explain. 127

Which number completes the inequality? 2/3 < _ < 7/9