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
Marat540 [252]
3 years ago
7

A tire store arranged its tires in rows from the most expensive tires to the lowest price. A set of tires from the first row cos

t $420. Each row had tires that were about 10% less than the tires in row before. Which row has a set of tires that cost about $75.00 per tire?
Mathematics
1 answer:
erica [24]3 years ago
8 0
1st row:   Cost = $420
2nd row: Cost = $420(0.9)
3rd row:  Cost = $420(0.9)²

By induction, the cost in the n-th row is
Cost = $420(0.9)ⁿ⁻¹

When the cost is $75, the row number, n, is given by
420(0.9)ⁿ⁻¹ = 75
(0.9)ⁿ⁻¹ = 75/420 = 0.1786

Take logs of each side.
(n-1)ln(0.9) = ln(0.1786) \\ n-1 =  \frac{ln(0.1786)}{ln(0.9)} =16.35 \\ n=17.35
Therefore
n = 17 (nearest integer)

Answer: Row 17

You might be interested in
About A red and a blue die are thrown. Both dice are fair. The events A, B, and C are defined as follows: A: The sum on the two
Flauer [41]

p(A) = \frac{1}{2}

p(B) = \frac{1}{6}

p(C) = \frac{1}{6}

P(A | C)=\frac{1}{2}

<u>Solution:</u>

The probability of an event is given as:

\text { probability of an event }=\frac{\text { number of favorable outcomes }}{\text { total number of outcomes }}

In throwing one die, the total number of outcomes = 6 { 1, 2, 3, 4, 5 , 6}

<em><u>First let us calculate p(A):</u></em>

The event is defined as: The sum on the two dice is even

Sum on two dice is even if and only if either both dice turn up odd or both even.

The odd outcomes in thowing a single die = 3 {1, 3, 5}

The even outcomes in throwing a single die = 3 {2, 4, 6}

The probability that both turn up odd is:

\text { probability of both die turing up odd }=\frac{3}{6} \times \frac{3}{6}=\frac{1}{4}

<em><u>Similarly, the probability that both turn up even is:</u></em>

\text { probability of both die turing up even }=\frac{3}{6} \times \frac{3}{6}=\frac{1}{4}

probability that the sum on two dice is even = probability that both turn up odd  + probability that both turn up even

\text { probability of sum on two dice is even }=\mathrm{p}(\mathrm{A})=\frac{1}{4}+\frac{1}{4}=\frac{1}{2}

Thus p(A) = \frac{1}{2}

<em><u>Let us calculate p(B):</u></em>

The event B is defined as: The sum on the two dice is at least 10

The total possible outcomes of two die is given as:

{(1,1) (1,2) (1,3) (1,4) (1,5) (1,6)

(2,1) (2,2) (2,3) (2,4) (2,5) (2,6)

(3,1) (3,2) (3,3) (3,4) (3,5) (3,6)

(4,1) (4,2) (4,3) (4,4) (4,5) (4,6)

(5,1) (5,2) (5,3) (5,4) (5,5) (5,6)

(6,1) (6,2) (6,3) (6,4) (6,5) (6,6) }

Since each individual die can turn up any of the numbers 1, 2, 3, 4, 5, 6 the event "sum of the two dice will be at least 10" is :

atleast 10 means that sum can be 10 or greater than 10

{(4,6), (6,4), (5,5), (5,6), (6,5), (6,6)}

Here favourable outcomes = 6

Total number of outcomes = 36

Hence, the probability that the sum of the two dice will be at least 10 is:

\text { probability that the sum of the two dice will be at least } 10=\frac{6}{36}=\frac{1}{6}

Thus p(B) = \frac{1}{6}

<em><u>Let us calculate p(C):</u></em>

The event C is defined as: The red die comes up 5

Favourable outcomes = {(1,5),(2,5),(3,5),(4,5),(5,5),(6,5)}

\text { probability of red die comes up } 5 \text { is the event }=\frac{6}{36}=\frac{1}{6}

Thus p(C) = \frac{1}{6}

<em><u>B) What is p(A l C)</u></em>

P(A | C)=\frac{p(A \cap C)}{P(C)}

\mathrm{A} \cap \mathrm{C}=\{(1,5),(3,5),(5,5)\}

p(A \cap C)=\frac{3}{36}=\frac{1}{12}

P(A | C)=\frac{p(A \cap C)}{P(C)}=\frac{\frac{1}{12}}{\frac{1}{6}}=\frac{1}{2}

Thus P(A | C)=\frac{1}{2}

8 0
3 years ago
Please help with 8.???
IRINA_888 [86]

Answer:

They are inverse functions

Step-by-step explanation:

A property of inverse functions is that if f(x) = a,  g(a) = x

We can plug in x = 3

f(1) = 3(3) - 2 = 7

That means that, supposing they are inverse functions, g(7) should equal 3

g(7) = \frac{7+2}{3} =3

It checks out

Another way to see if two functions are inverse is to swap the x and y of one of the functions.

ex. y = 3x-2\\-> x = 3y - 2\\-> x+2 = 3y\\-> y = \frac{x+2}{3}\\ \\

Since, after the swap, the functions are equal, we know it is an inverse function

5 0
3 years ago
What is the answer? Please Help!
Galina-37 [17]


What is the question you are struggling with I will try and help.


3 0
3 years ago
-3/12 - -2/3 can you please help me
MatroZZZ [7]

Answer:

5 /12

Step-by-step explanation:

8 0
4 years ago
A chef cooks rice using a 1: 2 ratio of dry rice to water. Her recipe calls for 9.5 cups of dry rice.
tigry1 [53]

Answer:

19 cups of water.

Step-by-step explanation:

1:2 ratio

1=9.5

2=9.5*2= 19

8 0
3 years ago
Other questions:
  • What is 2.4*10^8 - 3.0*10^8
    7·1 answer
  • 8.1 = 0.9a <br><br> a=?<br><br> Thank you!
    6·1 answer
  • 8 hr= how many min???<br> Please help fast!
    7·2 answers
  • abigail is putting tiles on a table top. she needs 48 tiles for each row of 8. each row will have 6 white tiles. the rest of the
    7·1 answer
  • write a polynomial with the zeroes: 5, -3, and -1+2x. I just need help with getting rid of the i. please help me.
    8·1 answer
  • Arianna has a coin collection. She keeps 4 of the coins in her box, which is 10% of the
    12·1 answer
  • Which of the following is an equivalent expression to the given expression using the commutative property of addition?
    13·2 answers
  • What is 400,000 rounded to 100,000
    8·1 answer
  • PLEASE HELP<br><br> I will mark brainliest
    10·1 answer
  • What's (2x) ^3 in expanded notation form?
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!