Hello!
A sample of Bromine-82 begins at 80 mL. We are given that this value will decrease by half of its current amount every 35 hours. First, we'll determine the number of times that 35 goes into 140. This will reveal the number of times we should divide the sample by 2:
140 ÷ 35 = 4
We have now proven that there are 4 periods of 35 hours in 140 hours. This means that we will divide the sample in half a total of 4 times, as follows:
1. 80 ÷ 2 = 40
2. 40 ÷ 2 = 20
3. 20 ÷ 2 = 10
4. 10 ÷ 2 = 5
We have now proven that an 80 mL sample of Bromine-82 will be reduced to only 5 mL after 140 hours. Therefore, the correct answer is 5 mL.
I hope this helps!
You have two choices.
The minimum possible cost to operate your bat factory for a day is $390,
and there are two quantities of bats that both cost that much.
One possibility:
Produce no bats at all per day. Zero. Nada. None.
Cost = 0.06(0)² - 7.2(0) + 390 = $390 per day.
The other choice:
Produce 120 bats per day.
Cost = 0.06(120²) - 7.2(120) + 390
= 0.06(14,400) - 7.2(120) + 390
= 864 - 864 + 390
= $390 per day.
If you produce any other number of bats in a day ... more than zero
but not 120 ... then it will cost you more than $390 to operate the factory
that day.
X would be 84 degrees, since its corresponding angle would be worth 84.
Hope this helped!
