Solving for the unknown variable...again
You may see problems like the following on the exam. If you can do this problem, you'll be able to do a lot that are similar. The key is knowing how to set up ratios and how to solve for an unknown variable.
A carpenter can make 5 tables in 13 hours. If he works at the same rate, which of these equations shows the number of tables (y) he can make in x hours?
Try it out before seeing the solution below.
Solution:
The ratio is tables to hours and you can set up a fraction like the following.
tables⁄hours = 5 tables⁄13 hours
5⁄13 = y⁄x
Now solve for y....cross multiply and divide
5x = 13y
5x⁄13 = y
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