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 formally valid if and only if the denial of the conclusion is incompatible with accepting all the premises. The validity of an argument depends, however, not on the actual truth or falsity of its premises and conclusion, but solely on whether or not the argument has a valid logical form. The validity of an argument is not a guarantee of the truth of its conclusion.