Percentage,cost price?

Question

The cost price of a computer is $1800.The shop owner earns 30% on the cost price,(a)What is the selling price of the computer? (b) If the same computer is now sold for $2070,what will be the percentage of the shop owner's earnings be??

Answer 1

1800=0.7x

1800/0.7=x

$2571.43 (rounded to nearest cent)

2070-1800 = profit

2070-1800 = 270

270/2070 = percent profit

13% = percent profit (rounded to nearest percent)