Now my question is do the F series VM's come under the 200 USD free trial
It depends on the machine size and Azure Region how much the F series VM cost. For example:
F1 (1 Core, 2 GB RAM) with a 128 GB Standard SSD in West US is about 89 US$ per month (VM is running all the time)
F4s (4 Cores, 8 GB RAM) with a 128 Premium SSD in West US is about 316 US$ per month (VM is running all the time)
The Azure Calculator is helpful to get the estimated price for Azure Services.
Hope this helps.
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