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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 B
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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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