Answer:
%15.5
Explanation:
200+(200x)=231
*x is the interest rate
so let's break down this question by going backwards. we can subract 200 from both sides since we cann easily get rid of +200. so you would get:
200x= 31
Now divide both sides by 200 to eliminate anything else, just to keep x alone.
x= 0.155
and a percent it would be %15.5
and to check:
200+(200*0.155)= 231