Answer:
They studied for a little more than an hour?
Step-by-step explanation:
7/12 of 60 Mins is 35 mins and 2/3 is 40 mins 40+35=75 mins
which is a little more than an hour, 15 mins more to be precise.
Answer:
A. 0.009899
B. 0.005624
Step-by-step explanation:
Data:
Let the probability that an item is defective = 
The probability that the item is not defective = 
The probability that the fifth item is defective = 
= 0.009899
Probability that one in 5 items is defective = 0.005624