RRB Junior Engineer / DMS / CMA 2015 · Question 19 of 480

The 12th term of the GP 1,-3,9,-27,...,is

Mathematics - Progressions

Aa. 312
Bb. -312
Cc. 311
Dd. -311Correct

Answer: D. d. -311

Explanation

GP1,-3,-9,-27... Here, a = 1,r = — = -3, n = 12 1 Tn=arn-i T\2 = (1) (-3)12-1 = (—3)11 = -311

Source: Arihant RRB JE Solved Paper 26-Aug-2015 (3rd Shift), Q91–150 — published solved-paper compilation (Q1–90 technical not included in this source) · memory-based

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