Tiya purchases some pen at the rate 8 pen per Rs.6 and he sells all the pen at the rate per 6 pen for Rs.8. Find overall profit or loss %.

77.77%

             Price    :    Qty

Buy :        6      :      8             ......(i)

Sell :        8      :      6             ......(ii)

(i) × 3 & (ii) × 4, to make the equal quantity.

             Price    :     Qty

Buy :     18       :     24

Sell :      32      :     24

Here,

C.P. of 24 articles = Rs.18

S.P. of 24 articles = Rs.32

Profit = 32 - 18 = Rs.14

Hence,

Profit percent = \(\frac{14}{18}\) × 100% = 77.77%