Percent decrease = (original number - new number) / original number....* 100
= (45 - 27.5) / 45.....* 100
= 17.5 / 45....* 100
= 0.3888 * 100
= 38.9 % decrease <== thats rounded
Step-by-step explanation:
so, that means we want to find the time t (days) after which N = No/2
because "half-life" means the amount of time until half of the substance has disappeared (or transformed into something else).
so, we have
No/2 = No × e^(-0.1481×t)
No = 2× No × e^(-0.1481×t)
1 = 2×e^(‐0.1481×t)
1/2 = 0.5 = e^(-0.1481×t)
ln(0.5) = -0.1481×t
t = ln(0.5)/-0.1481 = 4.680264555... ≈ 4.7 days
3x-5=2x-6
Move 2x to the same side as 3x.
3x-2x = x
X-5=-6
add 5 to the -6.
X = 5-6
X=-1
We have to find the mass of the gold bar.
We have gold bar in the shape of a rectangular prism.
The length, width, and the height of the gold bar is 18.00 centimeters, 9.21 centimeters, and 4.45 centimeters respectively.
First of all we will find the volume of the gold bar which is given by the volume of rectangular prism:
Volume of the gold bar 
Plugging the values in the equation we get,
Volume of the gold bar 
Now that we have the volume we can find the mass by using the formula,

The density of the gold is 19.32 grams per cubic centimeter. Plugging in the values of density and volume we get:
grams
So, the mass of the gold bar is 14252.769 grams