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 independent equations ensures a solution.
Q. A retailer sells only radios and clocks. If she currently has 44 total items in inventory, how many of them are radios?
I. The retailer has more than 28 radios in inventory.
II. The retailer has less than twice as many radios as clocks in inventory.
There are 2 variables (radios' number; r and clocks' number;c) and one equation (r+c=44). There are 2 more equations given by the conditions, so there is high chance (D) will be the answer,
For condition 1, r>28 and this is insufficient, as we do not get an unique value ofr r
For condition 2, r<2c and r<2(44-r), r<88-2r, 3r<88, r<88/3=29.33333...we also do not get the unique value of r, so this is insufficient
If we look at the conditions together,
28<r<29.33333..., and r=29. This issufficient and the answer becomes (C).
For cases where we need 1 more equation, such as original conditions with "1 variable", or "2 variables and 1 equation", or "3 variables and 2 equations", we have 1 equation each in both 1) and 2). Therefore, there is 59 % chance that D is the answer, while A or B has 38% chance and C or E has 3% chance. Since D is most likely to be the answer using 1) and 2) separately according to DS definition. Obviously there may be cases where the answer is A, B, C or E.
