Depending on breed, management and environment, the domestic horse (including draft horses) today has a life expectancy of 25 to 35 years. It is uncommon, but a few animals live into their 40s and, occasionally, beyond. The oldest verifiable record was Old Billy, a 19th-century horse that lived to the age of 62.
TRUE. Validity is a necessary condition for being sound. 14. FALSE. A valid argument can have a true conclusion and false premises (see #11); and if an argument does not have all true premises, then it is not sound.
An argument is termed formally valid if it has structural self-consistency, i.e. if when the operands between premises are all true the derived conclusion is always also true. In the third example, the initial premises cannot logically result in the conclusion and is therefore categorized as an invalid argument.