Why is my rotational mechanics homework solution not matching the given choices?

[Sarah00]

Homework Statement

Homework Equations

Net Torque = Moment of Inertia * Angular Acceleration
Net Force = Mass * Acceleration

The Attempt at a Solution

I first applied the first formula on the pulley, I found out that Tension Force = Acceleration
Then, I used Newton's second law on m1 which gave me: 120 - T = 12a ---> 120 - a = 12a ---> 13a =120 ---> a = 9.2

Which is not on the choices,,
any help please
thank you

 

[Qwertywerty]

I first applied the first formula on the pulley, I found out that Tension Force = Acceleration

What did you do here ? How is force of tension equal to acceleration ?

Hint : Is tension on both sides of the pulley the same ? Why / Why not ?
Also , your solution will require three equations .

Hope this helps .