Look at the first input and output, what do you see? Well, 5 is a multiple of 20, but if 5 is the output, this means that instead of multiplication we're doing division. How many times does 5 go into 20? 4 times, so that's our rule, I / 4 = O. If we use this rule for the rest of the questions, you get the answer.
To find the tax rate when given the initial price of an object and the final tax value, you use the equation: $350 * X = $22.75 (where X is the sales tax rate). Then solve: $22.75/$350 = .065
