Background: Jean Paul Getty (; December 15, 1892 - June 6, 1976) was an American-British industrialist. He founded the Getty Oil Company, and in 1957 Fortune magazine named him the richest living American, while the 1966 Guinness Book of Records named him as the world's richest private citizen, worth an estimated $1.2 billion (approximately $9.05 billion in 2017). At his death, he was worth more than $6 billion (approximately $25.80 billion in 2017).
Context: On July 10, 1973, in Rome, 'Ndrangheta kidnappers abducted Getty's 16-year-old grandson, John Paul Getty III, and demanded by telephone a $17 million payment (approximately $93.7 million in 2017) for the young man's safe return. However, "the family suspected a ploy by the rebellious teenager to extract money from his miserly grandfather." John Paul Getty Jr. asked his father for the money, but was refused.  In November 1973, an envelope containing a lock of hair and a human ear arrived at a daily newspaper. The second demand had been delayed three weeks by an Italian postal strike. The demand threatened that Paul would be further mutilated unless the victims paid $3.2 million (approximately $17.6 million in 2017): "This is Paul's ear. If we don't get some money within 10 days, then the other ear will arrive. In other words, he will arrive in little bits."  When the kidnappers finally reduced their demands to $3 million (approximately $16.5 million in 2017), Getty senior agreed to pay no more than $2.2 million (approximately $12.1 million in 2017) - the maximum that would be tax-deductible. He lent his son the remaining $800,000 (approximately $4.4 million in 2017) at 4% interest. Paul III was found alive in a Lauria filling station, in the province of Potenza, shortly after the ransom was paid. After his release Paul III called his grandfather to thank him for paying the ransom but, it is claimed, Getty refused to come to the phone. Nine people associated with 'Ndrangheta were later arrested for the kidnapping, but only two were convicted. Paul III was permanently affected by the trauma and became a drug addict. After a stroke brought on by a cocktail of drugs and alcohol in 1981, Paul III was rendered speechless, nearly blind and partially paralyzed for the rest of his life. He died 30 years later on February 5, 2011, at the age of 54.  Getty defended his initial refusal to pay the ransom on two points. First, he argued that to submit to the kidnappers' demands would immediately place his other fourteen grandchildren at the risk of copy-cat kidnappers. He added:  The second reason for my refusal was much broader-based. I contend that acceding to the demands of criminals and terrorists merely guarantees the continuing increase and spread of lawlessness, violence and such outrages as terror-bombings, "skyjackings" and the slaughter of hostages that plague our present-day world. (Getty, 1976, p. 139).
Question: how old was his grandson?. Whats the answer?
16-year-old