急!急!急! 超難數學題(7)

Question

<1>Mr Brown bought a car for$115000. He then used $10000 to upgrade the car and sold it to Miss White at $120000. Find Mr Brown's profit % or loss %.

<2>Mary paid $66 for a photo album which was marked at $75. Find the discount %.

<3>A man bought a chair at a discount of 35% of the marked price. If he paid $182, find the discount.

Answer 1

(1) Price of car = $115000
Updated price of car including upgrade = $115000 + $10000 = $125000
Sold to Miss White = $120000
Loss in the sale = $125000 - $120000 = $5000
Loss % = 5000/125000 x 100 = 4%

(2) Discount % is 75 x A% = 75 - 66
75 x A% = 9
A% = 9/75
A = 9/75 x 100
A = 12%

(3) Original price is 182 / 65% = 280
Discount = $280 - $182 = $98

Answer 2

(1).

Original price of a car when purchase = $115,000

Price of a car after upgrade = $115,000 + $10,000
= $125,000

Selling price of a car (to Miss White) = $120,000

Loss = $120,000 - $125,000
= $5,000

Percentage (%) loss = (5,000 / 125,000) * 100%
= 4% (loss)

(2).

Discount = $75 - $66
= $9

Discount percentage = (9/75) * 100%
= 12%

(3).
Original price of a chair = $182 / (1-35%)
= $280

Discount = $280 - $182
= $98