Answer:
t = 5?
Step-by-step explanation:
(40+80) + (8+2)
120+10
130
your answer would be 130
you group 40 and 80 and get the answer and then group 8 and 2
get answer to both then and then you add them together for the answer
Answer:
2
Step-by-step explanation:all of them can be divided by 2 and it is the smallest number.
Answer:
18 minutes
Step-by-step explanation:
A = A₀ (½)^(t / T)
where A is the final amount,
A₀ is the initial amount,
t is the time,
and T is the half life.
A = 140 when t = 10. Solve for the half life:
140 = 700 (½)^(10 / T)
0.2 = ½^(10 / T)
log 0.2 = (10 / T) log 0.5
10 / T = 2.32
T = 4.31
When A = 40, t is:
40 = 700 (½)^(t / 4.31)
0.057 = ½^(t / 4.31)
log 0.057 = (t / 4.31) log 0.5
t / 4.31 = 4.13
t = 17.8
Rounded to the nearest whole number, it takes 18 minutes.
