At this rate, what fraction of the distance between the two ports can the ferry travel on one hour?

Marina spent 1/5 of her money on a book. If she had $80 left after she brought the book, how much money did she have originally?

marissa [1.9K]

Answer:

Marina had 50$ originally

Step-by-step explanation:

80-1/5 of the money she spent for the books that she brought, The step by step process is how much money she had left behind from the books she brought seperate

8 0

3 years ago

Read 2 more answers

Ava said "There are only three hundred 3- diget numbers" is her statement true or faulse

Eduardwww [97]

Answer: False, there are actually 900 different three-digit numbers

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

Explanation:

The three digit numbers span from 100 to 999, including both endpoints.

This means we have 999-100+1 = 900 different three-digit numbers.

You subtract the endpoints (large-small) and add 1 to include the lower endpoint.

Here's a smaller example of why this works: say you had the set {1,2,3,4} and we wanted to count the number of items in this set. Clearly there are 4 items. Note how subtracting the endpoints 4-1 gets us 3 instead, so we add on 1 to include that left endpoint.

3 0

3 years ago

,.....................................

boyakko [2]

$\frac{x^{0}*y^{-3}}{x^{2}*y^{-1}} = \frac{1}{x^{2}*y^{3-1}} = \frac{1}{x^{2}*y^{2}}$

$Answer.C.) \frac{1}{x^{2}y^{2}}$

$\textbf{Spymore}$

4 0

4 years ago

At a certain bakery, the price of each doughnut is $1.50. Let the random variable D represent the number of doughnuts a typical

Solnce55 [7]

Using <em>statistical concepts</em>, it is found that the standard deviation of the probability distribution is of

$s = 1.5(1.9) = 2.85$

When a constant is multiplied to each data in a variable, both the <u>mean and the standard deviation</u> are multiplied by the constant.

In this problem, the standard deviation, which is the square root of the variance, is of:

$\sigma = \sqrt{\sigma^2} = \sqrt{3.6} = 1.9$

The price of each is of $1.5, hence:

$s = 1.5(1.9) = 2.85$

A similar problem is given at brainly.com/question/25718546

6 0

3 years ago

Determine the length and conductivity of a wire with diameter 4.2 mm constructed from an alloy of resistivity 3.2 x 10^-8 ohms-m

xz_007 [3.2K]

Answer:

1) L = 3.465 × 10^2; 31250000 S/m

2) terminal pd = 11V

3) ₦2

Step-by-step explanation:

1)

diameter of wire (d) = 4.2mm = 4.2 × 10^-3m

resistivity 3.2 x 10^-8 ohms-meter

Resistance(R) = 0.8 ohms

Area of wire (A)= πd^2 / 4

A =[ ( 22/7) * (4.2×10^-3)^2] / 4

A = [22/7 * 17.64×10^-6] / 4

A = 13.86×10^-6m^2

Recall:

Resistivity = (R ×A) / Length

Length = (R × A) / resistivity

Length(L) = [(0.8)(13.86×10^-6)] / 3.2 x 10^-8

L = (11.088 × 10^-6) / 3.2 x 10^-8

L = 3.465 × 10^2

Conductivity = 1/resistivity

Conductivity = 1/3.2 x 10^-8

Conductivity = 31250000 S/m

2)

Series resistor = 1.5 and 4.0 ohms

e.m.f (E) = 12V, internal resistance 'r' = 0.5

Recall :

I = E / (R + r)

Where I = current

R = circuit resistance

R = Rs = 1.5 + 4.0 (series connection) = 5.5

Recall : I = V/R

Where V = voltage ( terminal pd)

Therefore,

V/R = E/(R+r)

V/5.5 = 12/(5.5 + 0.5)

V/5.5 = 12/6

V/5.5 = 2

V = 5.5 × 2

V = 11V

3) power = 100W, t =10 hours

Energy consumed = power × time

Energy consumed = 100W × 10 hrs = 1000Whr

Recall: 1 KW = 1000 W

Therefore, energy consumed = 1KW

Cost of energy per KW = ₦2

Therefore, cost of lightning the lamp = ₦2 × 1KW = $2

4 0

4 years ago