Look at the last sentence of an algebra story problem. It usually tells you what the variables should stand for. The last sentence may also let you know if you should use a traditional formula for area, distance, interest, or volume.

For example:

Marilee and Scott ran in a race. Marilee finished two minutes before Scott, but she ran one less kilometer than Scott did. If they ran at the same rate and the total distance they ran (added together) was nine kilometers, then how long did it take them?

Just look at all those words. Go to the last sentence — and even the last phrase of the last sentence. It tells you that you're looking for the amount of time it took. The formula the last sentence suggests is d=rt (distance equals rate times time).