A certain substance has a half life of 1 hour. If you start with 3000 grams of the substance, how much will you have in 1 hour?

Horace's speedometer reads 60 miles per hour, but during a road test he finds that he was actually driving 58 mph. what is the percent error in horaces speedometer?

2men and 7 boys can do a piece of working 4 days. it is done by 4 men and 4 boys in 3 days how long would it take for 1man or one boy to do it alone

Which of the following constants can be added to x2 - 3x to form a perfect square trinomial?