1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
likoan [24]
3 years ago
14

The half-life of radioactive actinium (^227 Ac) is 22 years. How much will remain after 15 years? Find R first.

Mathematics
1 answer:
Llana [10]3 years ago
5 0
Use the formula below.

Let A_0 = 1 because you just want to know the percentage left. Usually that's the initial amount.

t = 15, the number of years past. n = 22, the half-life.

A=A_0(0.5)^{\frac{t}{n}} \\  \\ A=0.5^{\frac{15}{22}} \\  \\ A=0.62 = 62\%
You might be interested in
5) Using the terms "input" and "output" and the definition of a function, explain why this relationship is or is
Aleks [24]

Answer:

This relationship is a function

Step-by-step explanation:

While a function may not have two output values (y) assigned to the same input value (x), it may have two input values (x) assigned to the output value (y).

The table follows that rule

6 0
3 years ago
2) The following table presents the probability distribution of the number of vacations X taken last year for a randomly chosen
algol [13]

The mean of the discrete probability distribution is of 1.28.

<h3>What is the mean of a discrete distribution?</h3>

The expected value of a discrete distribution is given by the <u>sum of each outcome multiplied by it's respective probability</u>.

Then, considering the given distribution, the mean is given by:

E(X) = 0(0.13) + 1(0.61) + 2(0.15) + 3(0.07) + 4(0.04) = 1.28.

More can be learned about the mean of a discrete probability distribution at brainly.com/question/24855677

3 0
2 years ago
The robotics club has created 10 racing robots for the end of year science fair. each robot has the same chance of winning the r
Andreas93 [3]

Answer:  \frac{7}{120}

Step-by-step explanation:

8 0
3 years ago
a standard deck of cards missing the queen of hearts in the 2 of clubs what is the probability of pulling either an ace or a spa
Butoxors [25]
<h3>Answer:  8/25</h3>

=======================================================

Explanation:

In a standard deck, there are 52 cards.

If this deck is missing the queen of hearts and 2 of clubs, then we really have 52-2 = 50 cards in the deck.

There are 4 aces and 13 spades. Those values add to 4+13 = 17, but we need to subtract off 1 to account for the ace of spades counted twice. We have 17-1 = 16 cards that are either an ace, a spade, or both.

Or you can think of it like saying 13 spades + 1 ace of hearts + 1 ace of diamonds + 1 ace of clubs = 16 cards total.

-----------------

The event space has A = 16 cards in it, while the sample space has B = 50 cards.

The probability we're after is A/B = 16/50 = 8/25

5 0
2 years ago
Refer to your Expeditions in Reading book for a complete version of this text.
ahrayia [7]

Answer:

The 3rd one, The 1st one and The last one.

Step-by-step explanation:

6 0
2 years ago
Other questions:
  • Please help. I need answers quick. Please explain how you got your answer.
    15·1 answer
  • S the relation {(3, 5), (–4, 5), (–5, 0), (1, 1), (4, 0)} a function? explain. type your answer below
    8·1 answer
  • Mark and Sidney had identical pieces of wood.Mark used 1/3 of piece wood.Sidney used 5/8 if her pieces of wood. Who used more Ma
    8·1 answer
  • At a fundraiser breakfast, the bill for three glasses of orange juice and five pancake specials is $7.60, whereas the bill for o
    11·2 answers
  • What is the gcf of 24 40 and 56
    10·2 answers
  • How many 2/3 pieces can you cut from a 10 foot long board
    5·1 answer
  • Determine the equations that have a solution of x = 0.5? Select the two correct
    10·1 answer
  • What is the length of the hypotenuse?
    9·1 answer
  • Help me pls (: l: ):
    11·2 answers
  • Determine whether the three points are collinear:
    7·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!