Answer:
Given that,
The number of grams A of a certain radioactive substance present at time, in years
from the present, t is given by the formula

a) To find the initial amount of this substance
At t=0, we get


We know that e^0=1 ( anything to the power zero is 1)
we get,

The initial amount of the substance is 45 grams
b)To find thehalf-life of this substance
To find t when the substance becames half the amount.
A=45/2
Substitute this we get,


Taking natural logarithm on both sides we get,







Half-life of this substance is 154.02
c) To find the amount of substance will be present around in 2500 years
Put t=2500
we get,




The amount of substance will be present around in 2500 years is 0.000585 grams
Answer:
≈ 345.8 ft
Step-by-step explanation:
There is a right triangle formed by Bonnie's height (h) the ground and the angle of elevation.
Using the tangent ratio in the right triangle
tan20° =
=
( multiply both sides by 950 )
950 × tan20° = h , thus
h ≈ 345.8 ft ( to 1 dec. place )
It may be 114ft’ 8” or 1376 or 114.7
Explanation: see what options of answers they give you and pick one :)
Hope this helps! ٩( ᐛ )و
Answer: 35
Step-by-step explanation:
Given : A bag contains four red marbles, two green ones, one lavender one, three yellows, and one orange marble.
Total = 4+2+1+3+1=11
To find sets of four marbles include none of the red ones, we need to exclude red marbles when we count the total number of marbles.
Then, the total marbles(exclude red) =11-4=7
Now, the combination of 7 marbles taking 4 at a time is given by :-

Hence, the number of sets of four marbles include none of the red ones = 35
The answer is D ! U just have to see the numbers the left corner