Answer:
This is a typical radioactive decay problem which uses the general form:
A = A0e^(-kt)
So, in the given equation, A0 = 192 and k = 0.015. We are to find the amount of substance left after t = 55 years. That would be represented by A. The solution is as follows:
A = 192e^(-0.015*55)
A = 84 mg
Answer:
length of the photograph will be 4.2 in. after pressing the button 5 times.
Step-by-step explanation:
By pressing the button, every time size of the photograph gets reduced by 12%.
Therefore, the sequence formed by the reduced sizes of the photo will be a geometric sequence and the formula for the size of the reduced image will be,
L = 
Where l = Actual length of the photograph
L = length of the reduced image
n = Number of times the button has been pressed
For l = 8 in. and n = 5
L = 
= 
= 4.22 in
L ≈ 4.2 in.
Therefore, length of the photograph will be 4.2 in. after pressing the button 5 times.
Answer:
100 in²
Step-by-step explanation:
The area of the banner is equal to the area of the initial rectangle minus the area of the cutout triangle.
The rectangle has a height of 8 inches and width of 14 inches, so its area is:
A = (8 in) (14 in) = 112 in²
The triangle has a base of 8 inches and a height of 3 inches, so its area is:
A = ½ (8 in) (3 in) = 12 in²
So the area of the banner is 112 in² − 12 in² = 100 in².
Answer:
A is the answer.
Step-by-step explanation:
A fraction plus a fraction is equal to a fraction. An irrational number cannot be expressed as a fraction.
0.3333333 even though it looks like an irrational number it is actually: 1/3
3/5 is already a fraction so adding it with another fraction will NOT equal an irrational number (decimal)
-0.75 is equal to -3/4 (75/100 => 3/4). Same thing that applies above.
However, Pi cannot be expressed as a fraction exactly. You can round up like 3.14. However it is not the full number. So 3.141592654....+(3/4) is not going to add up perfectly into a fraction.
In short, a fraction is a rational number. Rational + Rational = Rational. Irrational + Rational = Irrational.
Answer: 5.75
Step-by-step explanation:
3/4=.75 then add the 5