Question
Applications of Ratio and Proportions: Be able solve percent increase/decrease problems, similarity problems, and area/volume scaling problems. Be able to explain the reasoning behind your strategy. (sections 7.5, 14.5 and 14.6) A store advertises a great deal on a fancy laptop, "$500 gets you the latest brand X laptop!". If this price includes the 8% sales tax, how much is the laptop before tax? Annoying company A used to sell chips in a 15oz bag for $3.29. Now they sell 13.5 oz for the same price ($3.29). What is the percent decrease in weight of chips for $3.29?
Explanation / Answer
a) let the original price is x
then according to given conditions
x+ 8%x = 500
x+0.08x=500
1.08x=500
x=500/1.08= 462.9630 $
thus original price of laptop is 462.9630 $
10)
% decrease in weight = loss in weight / ( original weight ) *100
= (15-13.5)/15 *100
=10%