Answer:
268 mg
Step-by-step explanation:
Let A₀ = the original amount of caffeine
The amount remaining after one half-life is ½A₀.
After two half-lives, the amount remaining is ½ ×½A₀ = (½)²A₀.
After three half-lives, the amount remaining is ½ ×(½)²A₀ = (½)³A₀.
We can write a general formula for the amount remaining:
A =A₀(½)ⁿ
where n is the number of half-lives
.
n = t/t_½
Data:
A₀ = 800 mg
t₁ = 10 a.m.
t₂ = 7 p.m.
t_½ = 5.7 h
Calculations:
(a) Calculate t
t = t₂ - t₁ = 7 p.m. - 10 a.m. = 19:00 - 10:00 = 9:00 = 9.00 h
(b) Calculate n
n = 9.00/5.7 = 1.58
(b) Calculate A
A = 800 × (½)^1.58 = 800 × 0.334 = 268 mg
You will still have 268 mg of caffeine in your body at 10 p.m.
Answer:
1.5
Step-by-step explanation:
Answer:
12(x+ 30)
Step-by-step explanation:
360 is the down payment and 12x is the monthly payment
With regards to the function as monthly we realise there are 12 months in a year so it could equally mean (12 months x amount) or $12 dollars multiplied by x)
Factorising We always put the highest common factor outside of the brackets when dealing with 2 numbers that can include variables such as x or 12x counting as one of the two.
12x+360
12(x+ 30)
Which is done as 12 x 30 = 360
We always try units first in numbers end in zero ie) 30 into 60 is x2 and 30 into 300 is 10 so our first highest common factor is 12 as its our largest number available from the smallest number given being 12.
So 12 is our highest common factor.
A common factor is a factor that is shared by two or more numbers. For example, a common factor of 8 and 10 is 2, as 2 is a factor of 8, and 2 is also a factor of 10. The highest common factor (HCF) is found by finding all common factors of two numbers and selecting the largest one
C because first you do ( 4+2 ) = 6 and 10 - 6 = 4
Answer:B, C, D
Step-by-step explanation:
I did the USATESTPREP
