Answer:
See it in the pic
Step-by-step explanation:
See it in the pic
-10w - 400 = o
w= weeks
o = new outstanding balance
Anita can clean 1/8 portion of the pool in 1 hour
Chao can clean 1/6 portion of the pool in 1 hour
Both of them working together can clean 1/8 + 1/6 = 7/24 portion of the pool in 1 hour
Therefore, it will take both of the working together 1/(7/24) = 24/7 or 3 3/7 hours to clean a typical pool.
Answer:
Every hour, the medicine concentration decays by a factor of 4%.
Step-by-step explanation:
The relationship between the elapsed time, <em>t</em>, in minutes, since the medicine was ingested, and its concentration in the bloodstream, <em>C</em> (<em>t</em>), is:

The decay function is:

Here,
<em>y</em> = final amount
<em>a </em>= initial amount
<em>r</em> = decay rate
<em>t</em> = time
From the provided expression the decay rate is:

Thus, every hour, the medicine concentration decays by a factor of 4%.
To answer problems like this you have to use binomial:
P (x > 1) = 1 – p (0
< x < 1) > .7
So:
1 – p (0) – p (1) >
.7
1 – (3/ 4) ^n – (3/ 4)
^n (n – 1 ) (1/ 4) > .7
Therefore n > 5.185,
and the smallest value of n so that we can satisfy the given condition is 6
(rounded up)
<span> </span>