QUESTION:
A battery was charged. When the charging began, it was 23 percent full. After 30 minutes of charging, the battery was 89 percent full. how fast did the battery charge and how long did it take?
Solution :
<u>Given</u>
- Initial amount of charge = 23%
- Amount after charge = 89%
<u>procedu</u><u>re</u>
Let the rate of charging be r .
r = (change in charge level) / (time interval) = (89% - 23%) / (30 min) = 2.2 % per minute
charge = (rate of charging)(time) + (initial charge)
100% = r*t + 23%
100% = (2.2 %/min)t + 23%
Solve for t and get
t = [(100 - 23) / 2.2]
Answer = 35 min
Answer:
The 15th visitor
Step-by-step explanation:
You have to find the LCM of the two numbers given by multiplying the chances that a visitor gets either a bumper sticker or a key chain.
1/3 x 1/5 = 1/15.
This means that every 15 people that visit the museum get both the bumper sticker and the key chain but since 15 is the lowest positive multiple of itself, the 15th visitor to the museum every day will be the first to get both items.
Answer:c is the correct answer
Step-by-step explanation:
A repair company's charge for repairing a certain type of copy machine fits the model y = 47.38 + 0.617x
where y is the number of dollars charged and
x is the number of minutes the repair person is on the job.
Therefore, to determine the number of minutes that it would take for the cost of repair to reach $130, we would substitute y =130 into the given model. It becomes
130 = 47.38 + 0.617x
0.617x = 130 - 47.38 = 82.62
x = 82.62/0.617 = 134 minutes
