Question 1033232
The easiest way is  look at the vertical change in water level, in inches.


{{{10*14*d=(4/3)pi*3^3}}}


{{{d=(4/3)pi*27/(140)}}}


{{{d=9pi/35}}}, the change in vertical water level.


That was not what the question asked for.  



Volume of the sphere:  {{{36pi}}}
Empty Volume in the Tank:  {{{10*14*2=280}}}
-
NOW the question asked how many spheres will fit before forcing the water to overflow?
-
Meaning is,   how many of 36pi is in 280?
{{{280/(36pi)}}}
{{{70/(9pi)}}}
{{{2.4757*approximately}}}
but you can only use whole values, NO fractional parts.
<b>2 glass spheres</b>.