People who never develop symptoms or are not yet showing symptoms (pre-symptomatic) might not know that they are infected but can still spread rona to others. Masks also offer protection to the wearer.
Answer:
$5.40
Step-by-step explanation:
First, figure out the cost of the items with tax; for Tommy we have 20*0.08 = 1.6, add that 1.6 to the 20 and his purchase is $21.6, for John we have 25*0.08 = 2, add 2 to his 25 and his purchase is $27. To find the difference we subtract 27-21.6 = 5.4 or $5.40
Answer and Step-by-step explanation: Spherical coordinate describes a location of a point in space: one distance (ρ) and two angles (Ф,θ).To transform cartesian coordinates into spherical coordinates:


For angle θ:
- If x > 0 and y > 0:
;
- If x < 0:
; - If x > 0 and y < 0:
;
Calculating:
a) (4,2,-4)
= 6
For θ, choose 1st option:
b) (0,8,15)
= 17


The angle θ gives a tangent that doesn't exist. Analysing table of sine, cosine and tangent: θ = 
c) (√2,1,1)
= 2

= 

d) (−2√3,−2,3)
= 5

Since x < 0, use 2nd option:



Cilindrical coordinate describes a 3 dimension space: 2 distances (r and z) and 1 angle (θ). To express cartesian coordinates into cilindrical:

Angle θ is the same as spherical coordinate;
z = z
Calculating:
a) (4,2,-4)
= 

z = -4
b) (0, 8, 15)
= 8

z = 15
c) (√2,1,1)
= 

z = 1
d) (−2√3,−2,3)
= 4

z = 3
Answer:
The answer is 162.
Step-by-step explanation:
To find the percentage of a number:
Turn the percentage into a decimal. 90% to .90
Multiply the decimal by the number you want to find the percentage of. .90 x 180
The answer is the product.