Ravi buys some toffees at 2 for a rupee and sells them at 5 for a rupee. His loss percent is = ?

Let the number of toffees bought be (2 x 5) = 10
C.P. of 10 toffees $$ = {\text{Rs}}{\text{.}}\,\left( {\frac{1}{2} \times 10} \right) = {\text{Rs}}{\text{.}}\,5$$
S.P. of 10 toffees $$ = {\text{Rs}}{\text{.}}\,\left( {\frac{1}{5} \times 10} \right) = {\text{Rs}}{\text{.}}\,2$$
$$\eqalign{ & {\text{Loss}}\% = \left( {\frac{3}{5} \times 100} \right)\% \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, = 60\% \cr} $$