How many ml are in 15 ml?

The question asks for the number of milliliters in 15 milliliters, which is a direct equivalence. Since 15 ml is being compared to itself, the answer is simply 15 ml. This highlights an important concept in measurement where a quantity is being referenced to itself, thus remaining unchanged. Recognizing and understanding such straightforward relationships in measurements is fundamental in medication administration, as it ensures accuracy in dosage delivery.