1 3xy-2 is not, because the exponent is -2 (exponents can only be 0,1,2,...). 2  2/(x+2) is not, because dividing by a variable is not allowed. 3  1/x is not either. â 4 x is not, because the exponent is Â½ (see fractional exponents).
There are 0.0648524 milliliter in a drop. 1 Drop is equal to 0.0648524 Milliliter. 1 drop = 0.0648524 mL. Used very commonly in medicine and cooking, a drop is a unit of volume defined as the volume of a liquid in one drop. It has been used since the 19th century and is considered one of the most roughly specified units of volume. Undoubtedly, the volume of a drop depends on the method or device used for producing drops.
Nocks, shafts, and arrows are generally measured by grain; a British unit based on the weight of a seed of barley. One grain is equal to 64.8 milligrams, or about 1/15th of a gram. Nocks commonly weigh from under 6 grains to over 20, or even higher for pin nock systems.