AWS EC2 instance: p2.xlarge or g2.2xlarge

I have to raise request to AWS.
I checked available instance types and found ‘g2.2xlarge’ is 30% cheaper than p2.xlarge.

type vCPU ECU Memory storage price
p2.xlarge 4 12 61 EBS Only $0.9 per Hour
g2.2xlarge 8 26 15 60 SSD $0.65 per Hour

Which one is suitable to do courses?
Please let me know.