Since
(density = mass/volume), we can get the mass/weight of the liquid by integrating the density
over the interior of the tank. This is done with the integral

which is more readily computed in cylindrical coordinates as

Answer:
32 years old.
Step-by-step explanation:
13 times 2 is 26, and 6 added to 26 is 32.
I hope this helps, have a nice day.