How long do I need to study to increase my score by ten points on quant and verbal?

Hello,
I’ve been studying for the gre using the one month plan but honestly it took me a whole month to go through just the first week of the plan. I just took my first practice test and scored a 282. I’m wanting to increase my score by 20 points. Do you think if I keep studying with the one month plan and actually stick to it my score will improve by 20 or will i need longer than that?

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