Answer :
Use the formula:
[tex]V=V_o+at\\ \\ 15.27=30.55-6t\\ \\ 6t=30.55-15.27\\ \\ 6t=15.28\\ \\ t=\frac{15.28}{6}=2.54 \ s [/tex]
[tex]V=V_o+at\\ \\ 15.27=30.55-6t\\ \\ 6t=30.55-15.27\\ \\ 6t=15.28\\ \\ t=\frac{15.28}{6}=2.54 \ s [/tex]