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Sum Inverse LCMs (Posted on 2008-10-03)

Each of P, Q, R, S and T are positive integers with P < Q < R < S < T. Determine the maximum value of the following expression.

[P, Q]^-1 + [Q, R]^-1 + [R, S]^-1 + [S, T]^-1

Note: [x, y] represents the LCM of x and y.

See The Solution Submitted by K Sengupta

Rating: 4.0000 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)

a stab

| Comment 2 of 7 |

Not sure this is optimum but . . .

1, 2, 4, 8, 16

= 1/2 + 1/4 + 1/8 + 1/16 = 0.9375

Posted by Leming on 2008-10-03 14:12:20

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