What is the total number of years that must pass before only 25.00 grams of an original 100.0-gram sample of?

This question is about half-life which means the time before half of the sample decomposes the half life of C-14 is around 5730y this sample goes through 2 half-lifes from 100 to 50 to 25 so 5730*2 = 11460yrs