word problem

Question

Town A and Town B were located close to each other, and recently merged into one city. Town A had a population with 10% native Americans. Town B had a population with 6% native Americans. After the merge, the new city has a total of 5000 residents, with 7.12% native Americans. How many residents did Town A and Town B used to have?

Answer 1

0.0712 * 5000 = 356 native Americans in the combined town

A + B = 5000

0.1A + 0.06B = 356

 

Use the 2nd expression to get A in terms of B (or vice versa) and replace in the 3rd expression to solve for A or B. Once you know one, you'll know the other.