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The selling price of 25 books is equal to the cost price of 41 books. Find the loss or gain percentage.
16100тАЛ%┬аgain
64 % gain
16100тАЛ%┬аloss
64 % loss
64 % gain
Use the formula: (SP┬аcountCP┬аcountтИТSP┬аcountтАЛ)├Ч100. Here: 2541тИТ25тАЛ├Ч100=2516тАЛ├Ч100=64%.
Selling price (SP) of 25 books = Cost price (CP) of 41 books.
Gain┬аpercentage=(Quantity┬аsold┬аfor┬аSPQuantity┬аsold┬аfor┬аSPтИТQuantity┬аbought┬аfor┬аCPтАЛ)├Ч100
Use the formula: (SP┬аcountCP┬аcountтИТSP┬аcountтАЛ)├Ч100. Here: 2541тИТ25тАЛ├Ч100=2516тАЛ├Ч100=64%.
Many students wrongly use the number of books bought as the denominator instead of the number of books whose SP matches the CP.
Set up the equation
Given that the Selling Price (SP) of 25 books equals the Cost Price (CP) of 41 books, we write: 25├ЧSP=41├ЧCP.
25тЛЕSP=41тЛЕCP
Find the ratio of CP to SP
Rearrange the equation to find the ratio of SP to CP: CPSPтАЛ=2541тАЛ.
CPSPтАЛ=2541тАЛ
Calculate the gain percentage
Since SP>CP, it is a gain. The gain is SPтИТCP=41тИТ25=16 units. Gain percentage is CPGainтАЛ├Ч100=2516тАЛ├Ч100.
Gain%=(2516тАЛ)├Ч100=64%
B is correct because the calculated gain percentage is 64%.
This type of 'item-based' profit/loss question is a standard in competitive exams; always identify which quantity corresponds to the denominator (the base value) to avoid the common inversion error.