Q. Find the least value of n for which 1 + 3+32 + ...................3n-1 > 1000. Share with your friends Share 0 Shruti Tyagi answered this Dear Student, 1+3+32+33....3n-1>1000Now this a GP with common ratio r=3Now apply sum of GP formula30×3n-13-1>1000⇒3n-1>2000⇒3n>2001now the least value of n which satisfies this inequality is 37=2187>2001Hence answer is n=7 Regards, 0 View Full Answer