Explanation

In this question, we'll consider two cases. First, say the tax was 10 percent. Technically, this is not allowed, but it's a limiting case. In that case the tax was and the total purchase would be . In the limiting case on the upper half, the tax is 50% greater, so it's . Then the total would be . So the total must be between $30.25 and $31.625. The range points of the correct answer can be exactly these, or they can be more expansive, but they cannot be narrower on either side. In other words, the interval we have identified must be contained with the correct answer.

The correct answer is (B).