Question

Mr Razali sold a laptop to Mr Azmi and earned a profit of 20%.Then,Mr Azmi sold the laptop to Shahid with the price RM 2400,which is a loss of 20%.What is the original price when Mr Razali bought that laptop?

Answer 1

The original price when Mr. Razali bought the laptop was $2500

Working backwards to solve the problem

If Mr. Azmi lost 20% when he sold the laptop for 2400, that means that he sold it for 80% of what he paid. If 2400 is 80% of what he paid, then to find out what he paid for it you would use this equation to determine what 100% would be:

$\frac{2400}{x} = \frac{80}{100}$
cross multiply to get:
240000 = 80x
3000 = x
Mr. Azmi bought the laptop for $3000

Mr. Razali sold the laptop for a profit of 20%, which means he sold it for 120% of what he paid for it. To determine how much he bought it for we would use this equation:
$\frac{3000}{x} = \frac{120}{100}$
cross multiply to get:
120x = 300000
x = 2500
Mr. Razali initially bought the laptop for $2500