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
lys-0071 [83]
3 years ago
13

What is the probability of rolling a prime number of a standard 20 sided die? (1 is not a prime number)

Mathematics
1 answer:
satela [25.4K]3 years ago
3 0

Answer:

2/5.

Step-by-step explanation:

The prime numbers from 1 to 20 are 2, 3, 5, 7, 11, 13, 17 and 19.

A total of 8.

So the probability of rolling a prime number is 8/20

= 2/5.

You might be interested in
(d) A car travels at an average speed of 80 km/h. How far does it travel in: (1) 2 hours? (11) 12 minutes?​
zepelin [54]
Answer is (1) 160 km in 2 hours and
(2) 16 miles in 12 minutes.

Step by step.
80 km / 1 hour = x km /2 hours
Cross multiply =
x = 160

The second one requires a little more math. Because we are looking at how far in minutes, we change the rate of 80km in 1 hour to 80 km in 60 minutes.
80 km / 60 = x / 12
Cross multiply
12x = 960
Solve for x by dividing both sides by 12
X = 16

I did the math on a print screen to explain the cross multiply.

3 0
1 year ago
You drive 140 miles in 2.5 hours and 300 miles in 5.5 hours. What is the rate of change ?
Sveta_85 [38]
The answer is one and five elevenths, or: 1 5/11

this is because 140/2.5 is 56 and 300/5.5 is 54 6/11.

56 - 54 6/11= 1 5/11
7 0
3 years ago
Miguel bikes 23 km per hour and starts at mile 10. Gabby bikes 28 km per hour and starts at mile 0. Which system of linear equat
7nadin3 [17]
The correct answer is D) Miguel:  d=23t+10, Gabby d=28t

We multiply the speed of each person by t, the amount of time.  This is where the 23t in Miguel's equation and the 28t in Gabby's equation come from.  The starting point is added to this, which leads to 23t+10 and 28t+0 or 28t.
8 0
3 years ago
Read 2 more answers
An object is propelled upward from the top of a 300 foot building. The path that the object takes as it falls to the ground can
serg [7]

Answer:

As per the statement:

The path that the object takes as it falls to the ground can be modeled by:

h =-16t^2 + 80t + 300

where

h is the height of the objects and

t is the time (in seconds)

At t = 0 , h = 300 ft

When the objects hit the ground, h = 0

then;

-16t^2+80t+300=0

For a quadratic equation: ax^2+bx+c=0         ......[1]

the solution for the equation is given by:

x = \frac{-b\pm \sqrt{b^2-4ac}}{2a}

On comparing the given equation with [1] we have;  

a = -16 ,b = 80 and c = 300

then;

t= \frac{-80\pm \sqrt{(80)^2-4(-16)(300)}}{2(-16)}

t= \frac{-80\pm \sqrt{6400+19200}}{-32}

t= \frac{-80\pm \sqrt{25600}}{-32}  

Simplify:

t = -\frac{5}{2} = -2.5 sec and t = \frac{15}{2} = 7.5 sec

Time can't be in negative;

therefore, the time it took the object to hit the ground is 7.5 sec

8 0
3 years ago
Samantha sends her son, Barry, to a preschool center on certain days. The cost of preschool is $45 per day along with a fixed mo
Hatshy [7]

Answer: Option D

D. 880 = 45d + 70; 18 days

Step-by-step explanation:

We know that the cost of preschool is $ 45 per day plus a monthly fee of $ 70.

We also know that a total of $ 880 was paid last month

To write an equation that represents this situation, let us call d the number of days that Barry attends school

So the cost was:

45d + 70 = 880

Now we solve the equation for the variable d

45d= 880-70

45d= 810

d= \frac{810}{45}

d= 18\ days

The answer is the option D

6 0
3 years ago
Other questions:
  • A parking garage charges $5.50 to park for 4 hours and $7.75 to park for 7 hours. If the cost is a linear function of the number
    15·2 answers
  • 696 to the nearest ten
    11·2 answers
  • if you a coin and roll a 6-sided die , what is the probability that you will flip a tails and roll a 2?
    9·1 answer
  • Based only on the information given in the diagram, which congruence
    10·2 answers
  • Easy Cooking is a cooking supply company. Last year, the company sold 24,620 ovens. This year, they sold 20% more ovens than tha
    6·1 answer
  • Which linear inequality is represented by the graph?
    11·2 answers
  • Match the given angle pair to their relationship using the figure beloe​
    5·1 answer
  • Use the chart below to answer the question
    8·1 answer
  • A straight line passing through A(3,2) and B(5,y) has gradient -2. find the value of y​
    13·2 answers
  • An isosceles triangle has two
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!