Question

Will upvote please help

Answer 1

T = 12 min,  T o = 80° C, T s = 50 °C,  T ( 12 ) = 60° C
60 = 50 + ( 80 - 50 ) · e^(-12k)
10 = 30 · e^(-12k)
e^(-12k) = 0.3333...
ln ( 0.333.. ) = - 12 k
- 12 k = - 1.1
k = ( - 1.1 ) : ( - 12 ) = 0.0916
Answer: D ) 0.0916