A spherical water tank with diameter of 26 meters supplies water to a small town. The town uses about 400 cubic meters of water per day. To the nearest day, how long would a full tank last if no water were replaced due to drought conditions.

i got 10.28 but that rounds up to 10.3

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!

not sure but it may be b, as i said i'm not sure.