If c & d are positive, is d an integer ?
i) c=d^3
ii) d=sqrt{c)
If c & d are positive, is d an integer
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- eagleeye
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i) c=d^3eccentric wrote:If c & d are positive, is d an integer ?
i) c=d^3
ii) d=sqrt{c)
c,d can be anything. d isn't necessarily an integer. Insufficient.
ii) d=sqrt{c)
Again, c,d can be anything. d isn't necessarily an integer.
Together:
Now From 1: c=d^3
From 2: c = d^2.
Hence d^3=d^2.
d^2(d-1)=0. Since d is positive, d is not 0. Hence d=1. So d is an integer. Sufficient.
C is correct.