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.
Answer:
b = 4
Step-by-step explanation:
5b + 4 = 24
5b = 20
b = 4
Answer:
your answer will be <em><u>B. HL Theorem </u></em>
Step-by-step explanation:
hope it helps you...
Answer:
455ways
Step-by-step explanation:
This is expressed as 15 C 3 ( C- combination)
The concept of combination is used when we talk about selection.
Now we are selecting 3 from a sample of 15
15 C 3 = 15! / (15-3)! 3! = 15 ×14×13×12!/12!×3×2
= 5 × 7 × 13 = 455ways
