Find the circumference of a circle with diameter = 38 in.

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Asmall foreign car gete 42 miles per gallon and user 35 gallons on a trip.gasoline costs $1.05 per gallon.what was the cost of gasoline per mile driver?

Mary used 1/7 of a spool of ribbon to complete 4 projects. she used the same amount of ribbon on each project. how much ribbon did she use on each project?