triathlon consists of three events: running, swimming, and bicycling

"18" is a song from the debut studio album by Australian rock band 5 Seconds of Summer

there are 28 countries in the European Union

Hellin's Law is the principle that one in about 89 natural pregnancies ends in the birth of twins

Hong Kong 97 is a 1994 thriller with Robert Patrick about the killing of high-ranking Chinese officials during the passage of Hong Kong from UK to China

most spiders have 4 pairs of eyes on the top-front area of the cephalothorax. The pattern they form varies from one family to another

the heads of the four United States presidents sculptured on Mount Rushmore are 18.3 meters tall

maximum enlistment age in US Marines

the ten, twenty, and fifty cent Euro coins are made of an alloy known as "Nordic gold", consisting of 89% copper, 5% aluminium, 5% zinc, and 1% tin

"XC 97: The Quest For the Cure" is a 2014 novel by Mark Dossey in which the head of a small lab that has developed a cure for cancer is shot before the official announcement of the discovery

there are 4 pecks in a bushel (a peck is an United States customary unit of dry volume, equivalent to 2 gallons)