Answer
Acceleration of smaller mass is $1.089m/s^{2}$ in upward direction.
Work Step by Step
$m_{1}=0.2kg$
$m_{2}=0.25kg$
As the configuration is same as Atwood machine,
so, $a=\frac{m_{2}-m_{1}}{m_{1}+m_{2}}g=\frac{0.25-0.2}{0.45}9.8=1.089m/s^{2}$
Hence, acceleration of smaller mass is $1.089m/s^{2}$ in upward direction.