Question

By selling 11 pencils for a rupee a man loses 10% how many pencils per rupee should he sell to gain 10%

Answer 1

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Answer 2

Answer:

9 pencils

Step-by-step explanation:

S.P. of 11 pencils = Re. 1

Loss% = 10%

S.P.= $\frac{100-L\%}{100}\times C.P.$

$1=\frac{100-10\%}{100}\times C.P.$

$1=\frac{90}{100}\times C.P.$

$\frac{100}{90}= C.P.$

$\frac{10}{9}= C.P.$

Now to find  how many pencils per rupee should he sell to gain 10%

S.P.= $\frac{100+P\%}{100}\times C.P.$

S.P.= $\frac{100+10}{100}\times \frac{10}{9}$

S.P.= $\frac{110}{100}\times \frac{10}{9}$

S.P.= $\frac{11}{1}\times \frac{1}{9}$

S.P.= $\frac{11}{9}$

Selling price of 11 pencils is $\frac{11}{9}$ to gain 10% profit

No. of pencils sold at Re.1= $\frac{11}{\frac{11}{9}}$

                                        = $9$

Hence he need to sell 9 pencils  per rupee to gain 10%.