What’s ..the .. answer

Answer:324Step-by-step explanation:a2a1=124=3a3a2=3612=3⇒ common ratio=r=3 and first term=a1=4no: of terms=n=9Sum of geometric series is given bySum=a1(1−rn)1−r⇒Sum=4(1−39)1−3=4(1−19683)−2=−2(−19682)=324