Question

A man has 80 pens. He sells some of these at 15% profit and the rest at 10%loss. Overall he gets a profit of 10%. Find how many pens were sold at 15% profit ?

Answer 1

Let the number of pen sold at 15% profit be $X$

Then the number of pen sold at 10% loss is $80-X$

According to question,$X\times \frac{115}{100}$+$(80-X)\times \frac{90}{100}$$=80\times \frac{110}{100}$

On solving it we get ,$X=64$

So $64$ pens were sold at 15% profit