Answer:
75
Step-by-step explanation:
Geometric means you should think common ratio (words like multiplication or division).
First term=3
Second term=15
What can you multiply to first to give you second term? Please say 5! Yes 5! Why? Because 3*5=15.
So 5 is called the common ratio. 5 is the number that you will multiply to a term to find the very next term.
So the third term would be 15*5=75