Answer:
(a) 3, 5 and 6
Step-by-step explanation:
In the experiment, 43 are to be given a gel that contains the tooth-whitening chemicals while the remaining 42 are to be given a placebo. Therefore, a placebo is used.
The 43 that will receive the gel are to be selected randomly.
After the experiment, the whiteness of the two groups will be compared to see the effect of the gel.
Therefore for the experiment to be completely random, 3, 5, and 6 apply.
(b)
For the experiment to be double-blind, the researchers who will evaluate the whiteness and interact with the subjects, and the subjects would not know which subjects received either the whitening gel or the placebo.
Volume of a cone = (π.R²)(h/3)
Diameter = 14cm then R=7 cm
Height = h= 2cm
Hence V=*π.7²)(2/3) ==> 98π/3 or 102.625 cm³
Area of shaded region = Area of larger circle - Area of smaller circle.
We know, Area of a Circle = πr²
So, A = πr₁² - πr₂²
A = π (r₁² - r₂²)
A = π(10.2² - 5.4²)
A = 3.14 (104.04 - 29.16)
A = 3.14 (74.88)
A = 235.12
In short, Your Answer would be 235.12 cm²
Hope this helps!
Answer:
156 feet larger
Step-by-step explanation:
Alright so 160% of 10 is 16 , now we do 16x16 = 256
Now we do 10x10 to find the old square feet which is 100
256-100=156
Hello,
Answer A
d :the distance in miles
t: the time in hours
v: the speed in miles/hours (vistesse)
d=v*t
==>d=40*4=160(mi)
d=55*x=160==>x=160/55=2.909090... (mi/(mi/h)=h)≈2.91(hours)
