As you already written, you have to use Newton's law
[tex] F=ma[/tex]
where F is the force, m is the mass, and a is the acceleration.
You already know the mass and the force, so you have to solve the equality for the acceleration:
[tex] a = \dfrac{F}{m} [/tex]
plug the given values:
[tex] a = \dfrac{150}{160} = \dfrac{15}{16} = 0.9375 [/tex]