Question

A store notices that a particular item in stock is never sold. This item could potentially make the store $7,862 daily, so the store manager begins an advertising campaign. On day 15 of the campaign, the store makes $3,547 in sales of this item. Assume the increase in sales follows the pattern of Newton's Law of Cooling (Heating). How many days of campaigning will it take for the store to make at least $5,039 from a single day of sales of this item?

a) 24 days

b) 20 days

c) 29 days

d) 26 days

Answer 1

Newton's law of colling

it is given that a particular item never got sold

let say t=infinity and T=7862

at t=0 T=0

hence the equation becomes

given condition is that '

at t=15 ,T=3547

therefor equation becomes

lets solve for k

put all values in first equation for T=5039

therefor answer is 26 that is option d........ thanks....