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Question
The harmonic mean of the numbers 2, 3, 4 is:
Options
`12/13`
12
`36/13`
`13/36`
Solution
`36/13`
Explanation:
HM = `"n"/(1/"X"_1 + 1/"X"_2 + 1/"X"_3 + ... + 1/"X"_"n")`
Here n = 3
∴ HM = `3/(1/2 + 1/3 + 1/4)`
= `3/((6 + 4 + 3)/12)`
= `3/13 xx 12`
= `36/13`
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