If a + 1, 2a + 1, 4a – 1 are in A.P., then the value of a is:
A. 1 B. 2 C. 3 D. 4 Answer: Option BShow Answer
Solution(By Apex Team)
$\begin{array}{l}\text{ Let }1^{\text{st }}\text{ term }=x=a+1\\
2^{\text{nd }}\text{ term }=y=2a+1\text{ and }\\
3^{\text{rd }}\text{ term }=z=4a-1\\
\Rightarrow y-x=z-y\\
\Rightarrow2y=x+z\\
\Rightarrow2(2a+1)=a+1+4a-1\\
\Rightarrow4a+2=5a\\
\Rightarrow a=2\end{array}$
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