It's about one-and-one-tenth times the number of Countries in the European Union.
In other words, the count of Countries in the European Union is 0.91 times 30.(a.k.a. EU) (2016 figures)
There are 28 member countries in the European Union, the latest member of which is Croatia. The EU is largely urban, with sixteen cities having a population of one million or more, and 75% of the population living in an urban area.
It's about three-fifths the number of Teeth in a Great White Shark's Mouth.
In other words, 30 is 0.63 times the count of Teeth in a Great White Shark's Mouth, and the count of Teeth in a Great White Shark's Mouth is 1.6 times that amount.(Carcharodon carcharias) (average; including developing rows)
A Great White Shark has 48 exposed teeth on their upper and lower jaws. Behind these exposed teeth are developing teeth — up to 300 in about 5 rows. The sharks will continuously lose and replace the exposed teeth throughout their lives.
It's about three-fifths the number of Countries in Africa.
In other words, 30 is 0.56 times the count of Countries in Africa, and the count of Countries in Africa is 1.8 times that amount.(2016 figures) (sovereign states recognized by the UN only)
The continent of Africa includes 54 sovereign countries recognized by the United Nations as of 2016. It is the second-most populous continent in the world, with 1.1 billion inhabitants.
It's about two times the number of Living Kings and Queens.
In other words, the count of Living Kings and Queens is 0.5 times 30.(2015 figures) (distinct Monarchs)
As of 2015, the world has fifteen Kings and Queens reigning over 45 countries. Of all these, Queen Elizabeth the II is the only reigning Queen; she has monarchical authority over the sixteen of the Commonwealth nations.
It's about two-fifths the number of Submarines in the US Navy.
In other words, 30 is 0.42 times the count of Submarines in the US Navy, and the count of Submarines in the US Navy is 2.4 times that amount.(a.k.a. Subs) (includes all types, all classes) (2015 figures)
The United States Navy maintains a fleet of 72 active submarines. A typical submarine goes to sea with a crew of about 140.
It's about one-third the number of Keys on a Piano.
It's about three-and-a-half times the number of Symohonies Composed by Beethoven.
In other words, 30 is 3.33333333333 times the count of Symohonies Composed by Beethoven, and the count of Symohonies Composed by Beethoven is 0.3 times that amount.(a.k.a. Ludwig van Beethoven)
Over the course of his life, Beethoven composed nine symphonies over the course of a twenty-four year period. After his death in early 1827, an estimated 20,000 Austrian citizens attended his public funeral.