a*b#0. Is |a|/|b|=a/b?
the OA is D, how is 2 sufficient to answer the question?
It's not. You're right answer is A, not D.a*b#0. Is |a|/|b|=a/b?
|a|/|b|=a/b is true if and only a and b have the same sign, meaning a/b is positive.
(1) |a*b|=a*b, means a and b are both positive or both negative, as LHS is never negative (well in this case LHS is positive as neither a nor b equals to zero). So, a/b is positive in any case. Hence |a|/|b|=a/b. Sufficient.
(2) |a|/|b|=|a/b|, from this we can not conclude whether they have the same sign or not: consider a=1, b=1 and a=1, b=-1 to see that these two sets give different answer to the question. Not sufficient.
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