Answer:
The minimum number of elastic pools and Azure SQL Database servers required is:
three elastic pools and one Azure SQL Database server.
Step-by-step explanation:
The above will ensure that the Azure regions of East US, North Europe, or South Africa North are grouped into their three elastic pools. Since cost minimization must be achieved, at the same time, one Azure SQL Database server will be enough to manage the 30 databases required, with one for each customer. Creating more than one Database server will increase the operational costs.