According to a set of standards, a certain type of substance can contain a maximum of 0.001% phosphorus by mass. If a sample of this substance has a mass of 140 grams, what is the maximum mass, in grams, of phosphorus the sample can contain to meet these standards?

The correct answer is .0014. It's given that a certain type of substance can contain a maximum of 0.001% phosphorus by mass to meet a set of standards. If a sample of the substance has a mass of 140 grams, it follows that the maximum mass, in grams, of phosphorus the sample can contain to meet the standards is \(0.001 \% \text { of } 140 \text {, or } \frac{0.001}{100}(140) \text {, }\) which is equivalent to (0.00001)(140), or 0.0014. Note that .0014 and 0.001 are examples of ways to enter a correct answer.