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Asked by hels145 | 3rd Jul, 2008, 06:07: PM

Expert Answer:

use the formula 1/F = 1/f + 1/f (this will give combined focal length)

now use the formula  P = 1/ F (this will  give power) of the combination.

 

Answered by  | 4th Jul, 2008, 11:44: AM

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