Question

nisha sold two sarees for 2185 each. On one she lost 5% ,while on the other she gained 15%.find her gain or loss per cent in the whole transaction

Answer 1

Given,
S.P (1 saree) = Rs. 2185

Case I:

S.P of one saree = 2185
loss = 5%
\begin{lgathered}C.P = \frac{100}{100-loss\% } \times S.P \\C.P = \frac{100}{100-5} \times 2185\\C.P = 2300\end{lgathered}​C.P=​100−loss%​​100​​×S.P​C.P=​100−5​​100​​×2185​C.P=2300​​ 

Case II:

S.P = 2185
gain = 15%
\begin{lgathered}C.P = \frac{100}{100+profit \%} \times S.P\\ C.P = \frac{100}{100+15} \times 2185\\C.P = 1900\end{lgathered}​C.P=​100+profit%​​100​​×S.P​C.P=​100+15​​100​​×2185​C.P=1900​​ 

Now,
Total S.P = 4370
Total C.P = 1900 + 2300
               = 4200
Gain = S.P - C.P
        = 4370-4200
        = 170
Gain % = gain/C.P x 100
             = 170/4200 x 100
             = 4.04 %