15 cm is longer.
In the USA, 15mm is half-inch, and 22mm is three-quarters inch. Lengths of pipe nipples in these sizes range from one and a quarter/one and a half, to six inches, in half-inch increments.
Then one is longer than the other.
(1/5) x 15 = 3 cm
21.9
In the metric systems, unlike other systems, there is only one unit for each measurement; e.g the only unit for length is the metre. For lengths much longer, or shorter, lengths we use prefixes to indicate the fraction or multiple of the metre. For short lengths the fractions are thousandths, millionths, billionths; for which the prefixes are milli-, micro-, and nano-. For longer lengths, the multiples are thousands, millions, and billions; for which the prefixes are kilo-, mega-, and giga-. The prefixes indicate the fraction,or the multiple of the base unit.
300 mm2
If it measures a maximum of 30cm, which most rulers do it's 15cm.
Two lengths
70.4 lengths
In the metric systems, unlike other systems, there is only one unit for each measurement; e.g the only unit for length is the metre. For lengths much longer, or shorter lengths we use prefixes to indicate the fraction or multiple of the metre.For short lengths the fractions are thousandths, millionths, billionths; for which the prefixes are milli-, micro-, and nano-.For longer lengths, the multiples are thousands, millions, and billions; for which the prefixes are kilo-, mega-, and giga-.The prefixes indicate the fraction or the multiple of the base unit.
One inch is 2.54 cm. One foot is 12 inches. Now you do the math.
There are a quarter million Planck lengths in a neutrino.