Answer:
6.6
Explanation:
The way to do this is to find the tax as a decimal. Worry about the 100 later.
54 * x = 3.56
Divide by 54
x = 3.56/54
x = .06593
Now use the 100
0.06592 * 100 = 6.593
But you want it rounded to the 1/10
So you should get 6.6 %