Question 30016
I see your first mistake ...

{{{ 160=16t^2+32t-320 }}} subtract 160 from both sides
{{{ 0 = 16t^2+32t-highlight(160) }}} You left it as 320
simple little mistakes like that will kill you.
{{{ 0 = 16t^2+32t-160 }}} divide by 16
{{{ 0 = t^2 + 2t - 10 }}} use the quadratic ...
{{{ x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
{{{ x = (-2 +- sqrt( 2^2-4*1*(-10) ))/(2*1) }}}
{{{ x = (-2 +- sqrt( 4-4*1*(-10) ))/(2*1) }}} 
{{{ x = (-2 +- sqrt( 4+40 ))/(2) }}}
{{{ x = (-2 +- sqrt( 44 ))/(2) }}}
{{{ x = (-2 +- 2sqrt( 11 ))/(2) }}} divide by 2
{{{ x = (-1 +- 1sqrt( 11 )) }}} assuming ONLY the possitive root ...
{{{ x = (-1 + 1sqrt( 11 )) }}} root out 11 = 3.31662 ......
{{{ x = -1 + 3.31662 }}}
{{{ x = 2.317 }}} rounded to the nearest thousandth