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Work Shown:
The discount is 30%, so you still have to pay 70% (because 100% - 30% = 70%)
70% = 0.70
Multiplying by 0.70 represents a decrease of 30%
Multiplying by 1.08 represents an increase of 8%, which is where the tax comes in.
The multipliers are: 0.70 and 1.08
So,
final price = (original price)*(discount multiplier)*(tax multiplier)
final price = 63*0.70*1.08
final price = 47.628
final price = 47.63
With this method, we can chain multiple discounts and/or taxes, fees etc in a very quick efficient manner.
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The (slightly) longer route might look like this
original price = 63
discount = 30% of original price = 0.30*63 = 18.90
price after discount = (original price) - (discount) = 63 - 18.90 = 44.10
note how this is the longer way of saying 63*0.70 = 44.10
Now apply the tax
tax = 8% of 44.10 = 0.08*44.10 = 3.528
final price after tax = 44.10 + 3.528 = 47.628 = 47.63
or you can say,
1.08*44.10 = 47.628 = 47.63
to get the same answer.
