fskilnik@GMATH wrote:GMATH practice exercise (Quant Class 1)
$$\,? = \left( {2 - {1 \over 3}} \right){\left( {1 + {1 \over 4}} \right)^{ - 1}}\left( {1 + {2 \over 5}} \right)\,\,$$
$$\left. \matrix{
2 - {1 \over 3} = {{2 \cdot 3} \over 3} - {1 \over 3} = {5 \over 3} \hfill \cr
1 + {1 \over 4} = {5 \over 4}\,\,\,\,\, \Rightarrow \,\,\,\,\,{\left( {1 + {1 \over 4}} \right)^{ - 1}} = {4 \over 5}\,\,\, \hfill \cr
1 + {2 \over 5} = {7 \over 5} \hfill \cr} \right\}\,\,\,\,\, \Rightarrow \,\,\,\,\,? = {5 \over 3} \cdot {4 \over 5} \cdot {7 \over 5} = {{4 \cdot 7} \over {3 \cdot 5}}$$
The correct answer is (D).
We follow the notations and rationale taught in the GMATH method.
Regards,
Fabio.