Question

the selling price of 10 articles is the same as the cost price of 11 articles find gain percent

Answer 1

Let the cost  price of  one  article   is  Rs.  100
Then  cost  price of  11 article  is  Rs. 100 X 11 = Rs. 1100

According  to  question

Selling  price  of   10  article  = Cost  price  of  11 article(Rs 1100)
Selling  price  of  1  article = Rs. 1100/10 = Rs 110

Gain %  =  110 -100  = 10%

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SHORT  TRICK  ={ (No. of  cost article/No. of selling article)X 100 } - 100
If  the  answer  is   positive  then  there  is  gain  and  if   answer  is  negative   then  there  is  loss

In  this  question  Ans {(11/10) X 100} -100 = 110 -100

Answer 2

let cp of 1article =X
then
cp of 11articles =11X
so of 10article =10X
profit =11X-10X=X
profit %=X/11X*100
=100/11 answer