Shabana bought 16 dozen ball bens and sold them at a loss equal to S.P. of 8 ball pens. Find her loss percent.

#### Solution

\[\text { Number of pens bought = 16 }\times 12 = 192\]

\[\text { Let the S . P of one pen be Rs } . x . \]

\[\text { Therefore, S . P of 192 pens = Rs . 192x }\]

\[\text { S . P of 8 pens = Rs . 8x }\]

\[\text { It is given that S . P of 8 pens is equal to the loss on selling 192 pens }. \]

\[\text { Therefore, loss = Rs . 8x }\]

\[\text { C . P of 192 pens = Rs . 576 }\]

\[\text { So, loss = C . P - S . P }\]

\[8x = 576 - 192x\]

\[200x = 576\]

\[x = \frac{576}{200} = 2 . 88\]

\[\text { Therefore, loss }= 8\left( 2 . 88 \right) = Rs . 23 . 04\]

\[\text { Loss % = }\frac{loss \times 100}{C . P}\]

\[ = \frac{23 . 04 \times 100}{576}\]

\[= \text { 4 % }\]