A bag contains three types of counter: purple squares, purple triangles and red triangles.
There are 14 red counters.
How many square counters are there?
Step 1 :Let P be the number of purple counters, T be the number of triangular counters, and S be the number of square counters. We have the following equations:
Step 2 :
Step 3 :
Step 4 :Solve the second equation for T:
Step 5 :Substitute T into the first equation:
Step 6 :Solve for P:
Step 7 :Since there are 14 red triangles, there are
Step 8 :Since 70% of the purple counters are triangles, there are
Step 9 :