Ask question

Ask question

All categories

3 years ago

8

Some four-digit numbers, such as 3003 and 6226, read the same forward and backward. If a boy selects a number from all four-

digit numbers, find the probability that it will read the same forward and backward.

1 answer:

Norma-Jean [14]3 years ago

3 0

<u>Answer:</u>

The probability of selecting such number = $\frac{90}{9000} = \frac{1}{100}$

<u>Explanation:</u>

4-digit numbers start from 1000 and ends at 9999

So, there are 9000 4-digit numbers present

There are 90 palindrome numbers (which reads the same forward and backward) present between 1000-9999. They are 1001; 1111; 1221; 1331; ... 1001; 1111; 1221; 1331; ... to 9669; 9779; 9889; 9999; 9669; 9779; 9889; 9999

Therefore, the probability of selecting such number = $\frac{90}{9000} = \frac{1}{100}$

You might be interested in

An art museum has a pentagon-shaped room. When drawn to scale on a coordinate grid, the corners of the room are points (18,20):

AURORKA [14]

Answer:

$2\ gal$

Step-by-step explanation:

we know that

the formula to calculate the distance between two points is equal to

$d=\sqrt{(y2-y1)^{2}+(x2-x1)^{2}}$

we have

$A(18,20),B(4,20),C(4,4),D(16.2),E(22.10)$

step 1

Find the distance AB

we have

$A(18,20),B(4,20)$

substitute in the formula

$d=\sqrt{(20-20)^{2}+(4-18)^{2}}$

$d=\sqrt{(0)^{2}+(-14)^{2}}$

$AB=14\ ft$

step 2

Find the distance BC

we have

$B(4,20),C(4,4)$

substitute in the formula

$d=\sqrt{(4-20)^{2}+(4-4)^{2}}$

$d=\sqrt{(-16)^{2}+(0)^{2}}$

$BC=16\ ft$

step 3

Find the distance DE

we have

$D(16.2),E(22.10)$

substitute in the formula

$d=\sqrt{(10-2)^{2}+(22-16)^{2}}$

$d=\sqrt{(8)^{2}+(6)^{2}}$

$d=\sqrt{100}$

$DE=10\ ft$

step 4

Find the distance AE

we have

$A(18,20),E(22.10)$

substitute in the formula

$d=\sqrt{(10-20)^{2}+(22-18)^{2}}$

$d=\sqrt{(-10)^{2}+(4)^{2}}$

$d=\sqrt{116}$

$AE=10.77\ ft$

step 5

Find out the area of the four walls

To determine the area sum the length sides and multiply by the height of the walls

so

$A=(AB+BC+DE+AE)h$

substitute the given values

The height of the walls is 10 ft

$A=(14+16+10+10.77)10$

$A=(50.77)10$

$A=507.7\ ft^2$

step 6

Determine the number of gallons needed to paint the four walls

we know that

one gallon of paint is enough to cover 400 square feet

using proportion

$\frac{1}{400}\ \frac{gal}{ft^2}=\frac{x}{507.7}\ \frac{gal}{ft^2}\\\\x=507.7/400\\\\x= 1.27\ gal$

Round up

$x=2\ gal$

5 0

3 years ago

Savings account deposit:$1,400rate:5%per year time:3 years

marysya [2.9K]

1610 if without interest

7 0

3 years ago

Because of the commutative property of multiplication, it is true that

rewona [7]

Answer:

It is Commutative

Step-by-step explanation:

An operation ∆ is said to be Commutative if a∆b=b∆a ∀ a,b ∈ ℝ.

Given the operation ∆ defined by:

a∆b=a X b

$a=\frac{3}{4}, b=4$

a∆b= $\frac{3}{4}X4$

$=\frac{3X4}{4}$ =3

Similarly, for the right hand side.

$(\frac{4}{3})^{-1}=\frac{3}{4}$

Therefore:

b∆a= $4X \frac{3}{4}$

$=\frac{4X3}{4}$ =3

These are the two ways of solving this problem and we have in fact shown that the operation is commutative as:

a∆b=b∆a=3

3 0

3 years ago

Find angle B <br> It’s says I need 20Characters to ask the question so here u go

Ber [7]

The answer is 50 degrees

Can I have brainliest

7 0

2 years ago

Solve in PEMDAS:<br> 3 + [2 + 3 X (6 X 3)]

sladkih [1.3K]

The answer should be 59

3 0

2 years ago