Question

A Shopkeeper bought some sweets at 11 for a rupee. he bought an equal no. of sweet at 10 for a rupee. HE sold all the sweets at 8 for a rupee. find his gain or loss percent.

Answer 1

Cost price of 11 sweets of first kind = Rs.1
And cost price of 10 sweets of second kind = Rs.1
So cost price of total 21 sweets = Rs.1 + Rs.1 = Rs.2
Then cost price of 8 sweets = $\frac{2}{21}\times 8=\frac{16}{21}$
And selling price of 8 sweets = Rs.1
Since S,P. > C.P.; so there is a gain.
So gain amount = $1-\frac{16}{21}=\frac{5}{21}$
Then gain percentage = $\frac{\left({\displaystyle \frac{5}{21}}\right)\times 100}{\left({\displaystyle \frac{16}{21}}\right)}=\frac{5}{21}\times \frac{21}{16}\times 100=\frac{125}{4}=31.25\%$