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# A person is to count 4500 currency notes.

Question:

A person is to count 4500 currency notes. Let $a_{n}$ denote the number of notes he counts in the $\mathrm{n}^{\text {th }}$ minute. If $\mathrm{a}_{1}=\mathrm{a}_{2}=\ldots=\mathrm{a}_{10}=150$ and $\mathrm{a}_{10}, \mathrm{a}_{11}, \ldots .$ are in an AP with common difference 2 , then the time taken by him to count all notes is :-

1. 24 minutes

2. 34 minutes

3. 125 minutes

4. 135 minutes

Correct Option: , 2

Solution: