Question

As you walk to your car, you notice that your tire is nearly flat! The initial psi level yesterday was 40 but it is now only 38 today. If this trend continues and the tire keeps losing the same percentage of air, how much should be left at the end of the week rounded to 1 decimal? (7 days later)

Answer 1

Explanation:

Given that:

Initial psi yesterday = 40 psi

psi today = 38 psi

If trend continues and tire loses the same percentage of air. How much air will be left in tire at the end of the week

1 week ( 7days)

Total loss after 7 days = (amount lost per day * number of days)

Total psi lost per day= [(40 - 38) = 2

% psi lost = (2/40) * 100

= 5%

Applying the exponential loss functin:

A = I ( 1 - r)^t

t = 7days ; r = 5% = 0.05 ; A = amount left ; I = Initial amount

A = 40(1 - 0.05)^7

A = 40(0.95)^7

A = 40 * 0.69833729609375

A = 27.933

A = 27.9 psi