French scientists used carbon-14 dating to determine the age of prehistoric wall paintings in the Niaux caves . They determined that the paintings were made using natural dyes approximately 13 thousand years ago.
1) In another 5.7 thousand years, the Niaux cave paintings will contain half as much carbon-14 as they currently do.
2) Cave paintings that are 7.3 thousand years old would contain twice as much carbon-14 as the Niaux cave paintings.