hi
-16t²+250 = 75
-16t² = 75 -250
-16t² = -175
 t² = -175 /-16
 t² = 175/16
Here there si two solutions :  t = [tex]\sqrt{175/16}[/tex]  and  t =  - [tex]\sqrt{175/16}[/tex]
However, as time cannot rewind,  we will  keep only positive solution
So t = [tex]\sqrt{175/16}[/tex]
 Â
in seconds  it will be  :  3.3 seconds