A marble statue is 39 years old and a limestone statue is 97 years old. In how many years will the limestone statue be twice as old as the marble statue?

Answer 1

Let the number of years be N. The marbel statue will be 39+N years old and the limestone statue will be 97+N years old.

Thus:
2(39+N)=(97+N)

Rearrange and solve for N.