Maths

A geometric progression has a third term of 20 band sum to infinity which is three times the first term. find the first term.

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  1. B3=20
    The sum=B1/(1-q)=3*B1 =>q=2/3
    B3=B1*q^2
    20=B1*4/9 =>B1=45

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  2. =90

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