Answer:
From first equation of motion:
[tex]{ \rm{v = u + at}} \\ { \rm{18 = 0 + (a \times 15)}} \\ { \rm{18 = 15a}} \\ \\ { \boxed{ \rm{ \: a = \frac{18}{15} \: m {s}^{ - 2} }}}[/tex]
For the second case:
[tex]{ \rm{v = u + at}} \\ { \rm{v = 0 + ( \frac{18}{15} \times 10)}} \\ \\ { \rm{v = 12 \: {ms}^{ - 1} }}[/tex]
