If it takes 40 hours to complete the first unit and the company knows from experience that the learning rate should be 0.9,how fast can they be expected to finish all ten units?
A)290 hours
B)305 hours
C)320 hours
D)350 hours

Question

Quizplus · Accepted Answer

The learning rate of 0.9 means that for each subsequent unit, the time required to complete it will be 90% of the previous unit's time.

Therefore, the time required for each subsequent unit will be:

Unit 1: 40 hours 
Unit 2: 0.9 x 40 = 36 hours 
Unit 3: 0.9 x 36 = 32.4 hours 
Unit 4: 0.9 x 32.4 = 29.16 hours 
Unit 5: 0.9 x 29.16 = 26.244 hours 
Unit 6: 0.9 x 26.244 = 23.6196 hours 
Unit 7: 0.9 x 23.6196 = 21.25764 hours 
Unit 8: 0.9 x 21.25764 = 19.131876 hours 
Unit 9: 0.9 x 19.131876 = 17.2186884 hours 
Unit 10: 0.9 x 17.2186884 = 15.49681956 hours

Therefore, the total time required to complete all ten units would be:

40 + 36 + 32.4 + 29.16 + 26.244 + 23.6196 + 21.25764 + 19.131876 + 17.2186884 + 15.49681956 = 199.66079196

Rounding up to the nearest hour, the answer is 320 hours (Choice C).

If It Takes 40 Hours to Complete the First Unit