Forget conventional ways of solving math questions. In DS, Variable approach is
the easiest and quickest way to find the answer without actually solving the
problem. Remember equal number of variables and equations ensures a solution.
Is a > b ?
(1) a/b = 7/10
(2) a = 70/100*b
==> transforming the original condition and the question using variable approach method, we have 2 variables (a,b) and in order to match the number of variables and equations we need 2 equations. Since there is 1 each in 1) and 2), C is likely the answer.
Using both 1) & 2) together, the answer is yes if a=-7, b=10, while the answer is no if a=7, b=10. Since the conditions and not suffiicent. the answer is E
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