Question

Five years ago, a typical 70” TV cost about $2400. Now a similar TV costs approximately $1680. What is the percent decrease in TV price?

Answer 1

Answer:

The percentage decrease in TV price after five years is 6.89

Step-by-step explanation:

Given as :

The cost of TV five years ago = $ 2400

The present cost of TV = $ 1680

Let The decrease percentage in five years = x

So, The cost of TV after T year = Present cost ×  $(1-\frac{Rate}{100})^{Time}$

Or, $ 1680 = $ 2400 ×  $(1-\frac{Rate}{100})^{5}$

Or, 0.7 =  $(1-\frac{Rate}{100})^{5}$  

Or,  $(0.7)^{\frac{1}{5}}$ = 1 - $\frac{x}{100}$

Or, 0.9311 = 1 - $\frac{x}{100}$

Or, $\frac{x}{100}$  = 1 - 0.9311

∴, $\frac{x}{100}$  = 0.0689

I.e x = 0.0689 × 100 = 6.89

Hence The percentage decrease in TV price after five years is 6.89 Answer