Speed is defined as quotient of distance and time.
![</p><p>s=(d)/(t)=(150)/(18)=8.33\dots</p><p>](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5wo1wtoscnbb0oki78rbtpo28exym03f0r.png)
Speed is a scalar value therefore we cannot determine its vector. Speed with vector is known as velocity and that is where we specify its vector because velocity is a vector value.
So the answer is 8.3 m/s.
Hope this helps.
r3t40