An egg is buried in 150 degree F sand in the desert After 3

An egg is buried in 150 degree F sand in the desert. After 3 minutes it is warmed to 80 degree F, and after 6 minutes, it is 100 degree F. How long will it be ready for lunch at 140 degree F?

Solution

there is a linear relation between the time anf temperature and we have two points (t,F)

t is the time in minutes

F is the temperaure in degree farhenhite

(3,80) and (6,100)

so we\'ll fine the equation using these two point by using the point slope form

y=mx+b

where m = slope=(y2-y1)/(x2-x1)

=> F - 80 = (100-80)/(6-3)*(t-3)

F-80 = 20/3(t-3)

F = 20t/3 + 60 , -----------> linear relation between time and temperature

now when F = 140 degree F

=> 140 = 20t/3 + 60

20t/3 = 80

t = 12 minutes

hence the egg will be ready for lunch at 140 degree F in 12 minutes.