Question

1.     With an 80% learning curve and an initial time of 200 minutes to do a job, at what number of repetitions will the job take less than 120 minutes?

Select one:

a. By the 6th necklace

b. By the 5th necklace

c. By the 7th necklace

d. By the 4th necklace

Answer 1

Learning rate equation is -

T_n=T₁n^b

where,
n = the unit number
T₁ = time taken to produce first unit = 200 mins
T_n = time taken to produce nth unit
p = the learning rate = 0.80
b = In p / ln 2 = ln 0.80 / ln 2

Let the job n take less than 120 mins

=> T_n=T₁n^b

=> T₁n^b = 120

=> 200*n^{(ln 0.80 / ln 2 )} = 120

=> n^{(ln 0.80 / ln 2 )} = 120/200

=> n = (120/200)^{1/(ln 0.80 / ln 2 )} = 4.88

Hence, Time for 5th necklace will be lesser than 120 mins

Correct option (b) By the 5th necklace