Answer:
20 days
Step-by-step explanation:
If the half-life is t, then every t days, the amount of the radioactive isotope will be cut in half.
(1/2)^(number of half-lives) = 3%
number of half-lives = ln(0.03) / ln(0.5)
This gives the number of half-lives as 5.06.
Then 300 days = (5.06)(length of 1 half-life)
length of 1 half-life = 300 / 5.06 = 59.29 days
Answer:
8 by 12 units
Step-by-step explanation:
Let w represent the width of the rectangle. Then the length is 1.5w. The perimeter is 4 more than 3 times this, so is (3(1.5w) +4) = 4.5w+4
The perimeter is given by the formula ...
P = 2(length + width)
Filling in the given values for the variables, we have ...
4.5w +4 = 2(w +1.5w)
4 = 0.5w . . . . . . subtract 4.5w and collect terms
8 = w . . . . . . . . . multiply by 2
length = 1.5×8 = 12
The rectangle is 8 units wide and 12 units long. The perimeter is 40 units.
Answer: Part A - C, Part B - 12 pieces
Step-by-step explanation:
<u>Part A:</u>
We know that 1/4 of Meredith's sub is bigger than 1/4 of Jim's sub, so we can set up an inequality.
Let Meredith's sub size = m; Jim's = j
Therefore, 1/4*m > 1/4*j
We can multiply both sides by 4:
m > j
Thus, the correct answer is C
<u>Part B:</u>
Since he had 1/4 of it left, that means he at 1 - 1/4 of it = 3/4 of his sub.
We can calculate the value of 3/4 * 16 = 12 pieces
Arrange from smallest to largest
-25, -12/4, 1/5, 18/5, 10
chose the middle number
1/5