The capital of egypt, and the center of the hellenistic, world was cairo
a. true
b. false

Cairo is the current capital of Egypt. It hasn't always been the capital, and for example Alexandria was the capital around 300 BC -600AD. It became the capital in the 10th century AD.

However, the whole statement is  definitely false as the capital of Hellenistic world was Alexandria 

Yes that is correct answer in 6