
Shortcut Trick
Total Selling Price (SP) = Initial Cost Price (CP) × (100 + P1)% × (100 − L2)%
SP = 37,800 × 108% × 96%
SP = 37,800 × 1.08 × 0.96 = 39,191.04
Rounding to the nearest rupee, we get 39,191.
∴ The correct answer is ₹39,191.

Alternate Method
Given:
Cost Price for S = ₹37,800
Profit percentage of S = 8%
Loss percentage of P = 4%
Formula Used:
Selling Price (SP) = Cost Price (CP) × (100 ± Profit/Loss %)/100

Calculations:
⇒ Price at which S sells to P (which is CP for P) = 37,800 × (108/100)
⇒ CP for P = 378 × 108 = ₹40,824
⇒ Price at which P sells to Q (SP for P) = 40,824 × (100 − 4)/100
⇒ SP for P = 40,824 × 0.96
⇒ SP for P = 39,191.04
⇒ Rounding to the nearest rupee, we get ₹39,191.
∴ The correct answer is ₹39,191.

Additional Information
Successive Percentage Change
When a value changes by x% and then y%, the net effective change is given by [x + y + (xy/100)]%.
Relation between CP and SP
Selling Price = Cost Price + Profit OR Cost Price − Loss. Profit % and Loss % are always calculated on the Cost Price unless stated otherwise.
Rounding Rules
If the decimal part is 0.5 or more, round up to the next integer. If it is less than 0.5, round down to the current integer.