Let us assume the number of student's in Zoe's class = x
Then
Number of students that have pets = 4x/5
Number of students that have rodents as pets = (1/8) * (4x/5)
= x/10
Number of students in Zoe's class
that have pets that are not rodents = (4x/5) - (x/10)
= (8x - x)/10
= 7x/10
I hope that the procedure is clear enough for you to understand and this is the answer that you were looking for.
Dot product is
a*b = |a|*|b|*cosα.
In our case
u*u =|u|*|u|*cos 0
u*u =|u|*|u|
12=|u|²
|u|=√12=√(4*3)=2√3
Answer: <span>D. 2√3</span>
Answer:
25%
Step-by-step explanation:
Let v, t be the current average speed and the time taken to reach the school respectively.
As distance = speed x time, so,
distance, d=vt...(i)
Let V be the new average speed in order to to take 20% less time than t.
So, time taken with speed V = t-20% of t = t- 0.2t= 0.8t
As distance is constant, so
d= V(0.8t)= 0.8Vt
hBy using equation (i), we have
0.8Vt = vt
0.8 V = v
V= v/0.8=1.25v
Therefore, the percentage increase in the average speed = ![\frac{V-v}{v}\times 100](https://tex.z-dn.net/?f=%5Cfrac%7BV-v%7D%7Bv%7D%5Ctimes%20100)
![=\frac{1.25v-v}{v}\times 100](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1.25v-v%7D%7Bv%7D%5Ctimes%20100)
=25%
Hence, the percentage increase in the average speed is 25%.
For this case we have the following equation:
s = 300 / d
Where,
s: the speed of the current in a certain whirlpool
d: the distance from the center of the whirlpool
We have then that:
If the distance from the center of the whirpool is large, the speed is small.
If the distance from the center of the whirlpool is very small, the speed tends to infinity
Answer:
Large distance, small speed.
Short distance, speed tends to infinity.