Question

15 In a shop, all normal prices are reduced by 20% to give the sale price.

The sale price of a TV set is then reduced by 30%.
Mary says,
"30+ 20 = 50, so this means that the normal price of the TV set has been
reduced by 50%."
Is Mary right?
You must give a reason for your answer.

Answer 1

Mary is incorrect

Explanation:

Mary is incorrect

The additional reduction of 30% is not on the original normal price but the original price discounted by 20 % originally

The total discount will be less than 50%, actually 44%

To prove Mary is wrong, let's take the normal price of the TV as $100

After discount of 20% which is a discount of 0.20 x 100 or $20, the reduced price is $100-$20 = $80

The additional reduction is on this price so the additional discount = 30% of $80 = 0.3 x 80 = $24

The final price of the TV is $80 - $24 = $56

The total discount = 100 - 56 = 44

Percent discount = Discount amount/Original Price x 100

= 44/100 x 100 = 44%