JEE Math Practice Question
If $${{a_1},{a_2},....{a_n}}$$ are in H.P., then the expression $${{a_1}\,{a_2} + \,{a_2}\,{a_3}\, + .... + {a_{n - 1}}\,{a_n}}$$ is equal to
- A.$$n({a_1}\, - {a_n})$$
- B.$$(n - 1)({a_1}\, - {a_n})$$
- C.$$n{a_1}{a_n}$$
- D.$$(n - 1)\,\,{a_1}{a_n}$$
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