Answer:
Answer is 13.3%
Step-by-step explanation:
- 90 percent of the batteries will last 10 hours or exceed.
- 12 percent of the batteries will last 15 hours or more.
If the likelihood of these batteries is to hold for the given time period, then, out of one thousand (1000) batteries produced, nine hundred (900) of the batteries will have long lasted 10 hours or longer and 120 of them will have lasted 15 hours or more.
The 120 which have lasted 15 hours or more must have lasted at most 10 hours or more, so they are part of the bunch that lasted 10 hours of more.
They are 12% of the total of 1000 batteries produced, but they are 15% of the 900 batteries that lasted 10 hours or more, Why? view the following:
- 120 / 900 = 0.1333 = 13.3%
The solution which seems to be that 13.3 percent of the batteries that prolonged 10 hours or more lasted 15 hours or longer.
