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
Kruka [31]
3 years ago
8

a teacher had 21 red pens. if the ratio of red pens to blue pens she owned was 3:1 , how many pens did she have in total

Mathematics
2 answers:
snow_lady [41]3 years ago
8 0
She had 21:7 because if you multiply 3:1 by 7 each it is 21:7 so she had 7 blue pens
erma4kov [3.2K]3 years ago
5 0
There are 21 red pens. For every 3 red pens, there is 1 blue pen.
Let's make these into a fraction equation.
21/p=3/1
p is the number of blue pens we have yet to find.
First, cross multiply.
21x1=21
px3=3p
Now, we have an equation of
21÷3p
We set it equal to 1, and we solve it.
21÷3p = 1
(21÷3p)×3p=1×3p
21=3p
21÷3=(3p)÷3
7=p
So, if there are 21 red pens, there are 7 blue pens.
We add these together to find the total number of pens the teacher has.
21+7=28
The teacher has 28 pens total.
You might be interested in
Given right triangle MUD such that mD = 23.1 and d = 38, which of the following statements are true? Round to the nearest hundre
Zigmanuir [339]
∠M=90°-23.1°=66.9° - it's a right answer.

u=d/sin∠D=97.25
m=cos∠D*u=89.52
4 0
3 years ago
Read 2 more answers
During a figure skating routine, Jackie and Peter skate apart with an angle of 15° between them. Jackie skates for 5 meters and
Fantom [35]

Answer:

Ans = 2.53m

Step-by-step explanation:

It is a simple law of Cosine, on a right-angle triangle draw the length as 5 and the base as 7 the angle is 15°. Find x.

So x = 5² +7² - 2 (5) (7)cos 15°

Solve this and you get your answer.

Hope this was helpful :)

7 0
3 years ago
Whic of the following are valid names for the triangle below? Check all that apply.
emmasim [6.3K]

Answer:

A, C, E

Step-by-step explanation:

As long as all the 3 letters(D, K, and M) are included, it should be a valid name. These are the 3 points in the triangle afterall.

4 0
3 years ago
Along with this one please
Anarel [89]
X=5.2
Hope this was helpful
8 0
3 years ago
Which is the equation of the line that passes through the points (4, 3) and (6, 2)?
Andrew [12]

Answer:

answer is c hope this helps

Step-by-step explanation:

3 0
3 years ago
Other questions:
  • AjaoaoaYeah ha najakajak
    10·1 answer
  • The mean hourly salary of the 10 employees at a fast­food restaurant is $8.25. One of the employees earning $6.50 an hour leaves
    15·1 answer
  • True or False. A sinusoid is a function whose values repeat based on positions of a point that moves around a circle.
    14·2 answers
  • Which quadratic function has Vertex (-1,4) and passes through (4,19) <br> HELP
    7·1 answer
  • A football field measures 360 feet by 160 feet. What is the area of the field?
    7·2 answers
  • 2/3 of all your boks are fiction 1/6 of those are historical fiction. what fraction of all your books are historical fiction ​
    9·1 answer
  • Find the solutions to x2 = 20.
    12·2 answers
  • Distance for 3 minutes and at the speed of 17m/s​
    5·1 answer
  • What is the volume of a hemisphere with a radius of 29 m, rounded to the nearest tenth of a cubic meter?
    6·1 answer
  • Translate each English phrase in the following problem into an algebraic expression and set up the related equation. Let z be th
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!