Answer:
the rate of change in volume is dV/dt = 4π mm³/s = 12.56 mm³/s
Step-by-step explanation:
since the volume V of a cylinder is related with the height H and the radius R through:
V = πR²*H
then the change in time is given by the derivative with respect to time t
dV/dt = (∂V/∂R)*(dR/dt) + (∂V/∂H)*(dH/dt)
the change in volume with radius at constant height is
(∂V/∂R) = 2*πR*H
the change in volume with height at constant radius is
(∂V/∂H) = πR²
then
dV/dt = 2π*R*H *(dR/dt) + πR²*(dH/dt)
replacing values
dV/dt = 2π* 2 mm * 20 mm * (-0.1 mm/s) + π (2 mm) ²* 3 mm/s = 4π mm³/s
dV/dt = 4π mm³/s = 12.56 mm³/s
Answer:
B
Step-by-step explanation:
The order does not matter. The intersection point will be the same regardless of the order the arcs are drawn in.
We can let r be the number of food tickets and f be the number of food tickets.
Since Alana can spend at most $40, that means the total of price bought for r and f must be less than or equal to $40. In addition, since Alana buys at least 16 tickets, this also means that the total of r and f is 16. Mathematically, we have these inequalities:
(1) 4r + 2f ≤ 40 and
(2) r + f ≥ 16
Multiplying -2 in (2), we have
4r + 2f ≤ 40
-2r - 2f ≤ 32
Adding both inequalities,
2r ≤ 8
r ≤ 4
Since r must be less than or equal to 4.Thus the answer is <span>A.</span>
Answer:
a. The average number of hashtags used in a social media post from a marketing agency is different than 7 hashtags.
Step-by-step explanation:
A social media platform states that a social media post from a marketing agency has 7 hashtags, on average.
This means that at the null hypothesis, we test if the mean is 7, that is:

A digital marketing specialist studying social media advertising believes the average number of hashtags used in a post from a marketing agency is different than the number stated by the social media platform.
Keyword is different, so at the null hypothesis, we test if the mean is different of 7, that is:

Thus, the correct answer is given by option a.