Is a > b ?

(1) a/b = 7/10

(2) a = 70/100*b

both statements essentially say the same thing.. ratio: a:b=7:10 => 10a=7b;

now just plug in some values to see if you can get any definitive answers:

assume a=7, b=10 or a=14, b=20 and so on.... (a< b)

but there are negative answers as well.... a=-7, b=-10 => a > b

I would go with E.....

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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Is \(a>b \quad?\)

(1) \(\frac{a}{b} = \frac{7}{10}\)

Taking \(a = 7\) and \(b = 10,\quad \frac{a}{b}=\frac{7}{10}\)

Is \(a>b ? : No\) ; as \(7<10\).

Taking \(a = - 7\) and \(b = -10,\quad \frac{a}{b} = \frac{-7}{-10}=\frac{7}{10}\)

Is \(a>b ? : Yes\) ; as \(-7>-10\).

Statement \(1\) alone is not sufficient.

(2) \(a = \frac{70}{100}*b\)

\(a = \frac{70}{100}*b\) can be reduced to \(a = \frac{7}{10} *b\)

Taking \(a = 7\) and \(b = 10,\quad a=\frac{7}{10}*b\)

Is \(a>b ? : No\) ; as \(7<10\).

Taking \(a = - 7\) and \(b = -10,\quad a = \frac{7}{10}b\)

Is \(a>b ? : Yes\) ; as \(-7>-10\)

Statement \(2\) alone is not sufficient.

As Statement (1) and statement (2) are the same with only exception that in statement 1, b cannot be zero while statement 2, b can be 0.
Combining both will also be insufficient to answer: Is a > b ?