Rocket motor thrust calculation from acceleration data

[Cb8]

Homework Statement

A 2.0x104 kg rocket has a rocket motor that
generates 2.7×105 N of thrust.
A) What is the rocket's initial upward acceleration in m/s^2.

B) At an altitude of 5000 m the rocket's acceleration has
increased to 6.0 m/s?. What mass of fuel has it
burned in kg.

Relevant Equations

2.0x10^4 kg Rocket
2.7x10^5 N of thrust

I tried A with the solution of 9.73 and 8.69 both wrong.

 

[haruspex]

Homework Statement:: A 2.0x104 kg rocket has a rocket motor that
generates 2.7×105 N of thrust.
A) What is the rocket's initial upward acceleration in m/s^2.

B) At an altitude of 5000 m the rocket's acceleration has
increased to 6.0 m/s?. What mass of fuel has it
burned in kg.
Relevant Equations:: 2.0x10^4 kg Rocket
2.7x10^5 N of thrust

I tried A with the solution of 9.73 and 8.69 both wrong.

Please explain how you arrived at those solutions.