answer.
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
pishuonlain [190]
2 years ago
5

In a library, the ratio of maths books to science books is 3 : 2 and the ratio of science books to history books is 1 : 3. If th

e total number of books is 220, how many maths books are there?
Mathematics
1 answer:
trapecia [35]2 years ago
6 0

Answer:

60 maths books

Step-by-step explanation:

<u>Let the following be:</u>

  • Maths books = m
  • Science books = s
  • History books = h

<u>And we have ratios and sum:</u>

  • m/s = 3/2
  • s/h = 1/3
  • m+s+h = 220

<u>From the ratios we get:</u>

  • m = 3s/2
  • h= 3s

<u>Considering the above in the sum of books:</u>

  • m+s+h = 220
  • 3s/2 + s + 3s = 220
  • 3s + 2s + 6s = 2*220
  • 11s = 440
  • s = 440/11
  • s = 40

<u>Number of maths books:</u>

  • m = 3s/2 = 3*40/2 = 60
You might be interested in
How to derive the formula for the surface area of a cylinder?
DaniilM [7]
Bnfvbdfv tfukuhyghfv5erfdgtuhjuh

7 0
2 years ago
If a large cylinder has a volume of 28260 cubic cm, how many cylinders can be filled out of the large cylinder if the small cyli
inysia [295]
Hi,

To find the number of small cylinders that fit inside the big cylinder. You need to divide volume of small cylinder with the volume of big cylinder. We do this by using formula to calculate volume of cylinder:


v = \pi \times  {r}^{2}  \times h


To find radius just divide diameter with 2.

v = \pi \times   {2}^{2}  \times 6 \\ v = \pi \times 4 \times 6 \\ v = \pi \times 24 \\ v = 3.14 \times 24 \\ v = 75.4 {cm}^{3}


Now just division:

28260 \div 75.4 = 374.8

Answer: You could fit 374.8 smaller cylinders inside a big cylinder.

Hope this helps.
r3t40
7 0
2 years ago
The staff of Mr. Wayne Wertz, VP of Operations at Portland Peoples Bank, prepared a frequency histogram of waiting time for walk
Delvig [45]

Answer:

jidedjiji

Step-by-step explanation:

cdsfddddssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss

8 0
2 years ago
Read 2 more answers
Josh travels frequently. For a particular airline, it takes 20 minutes for the first bag to arrive in baggage claim after a flig
Orlov [11]

Using the uniform distribution, it is found that:

A,B) 0.3 of the time does it take longer than 27 minutes for Josh’s bag to arrive in baggage claim.

C) 20% of the time does Josh’s bag arrive in less than 22 minutes.

--------------------------

An uniform distribution has two bounds, a and b.  

The probability of finding a value of at lower than x is:

P(X < x) = \frac{x - a}{b - a}

The probability of finding a value between c and d is:

P(c \leq X \leq d) = \frac{d - c}{b - a}

The probability of finding a value above x is:

P(X > x) = \frac{b - x}{b - a}

--------------------------

  • In the graph, we have that the distribution is uniform between 20 and 30 minutes, thus a = 20, b = 30

--------------------------

Itens a and b:

  • Above 27 minutes, thus:

P(X > 27) = \frac{30 - 27}{30 - 20} = 0.3

0.3 of the time does it take longer than 27 minutes for Josh’s bag to arrive in baggage claim.

--------------------------

Item c:

  • Less than 22 minutes, thus:

P(X < 2) = \frac{22 - 20}{30 - 20} = 0.2

0.2*100 = 20%

20% of the time does Josh’s bag arrive in less than 22 minutes.

A similar problem is given at brainly.com/question/15855314

6 0
2 years ago
in a random sample of 200 people, 154 said that they watched educational television. fine the 90% confidence interval of the tru
melisa1 [442]

Answer:

[0.7210,0.8189] = [72.10%, 81.89%]

Step-by-step explanation:

The sample size is  

n = 200

the proportion is

p = 154/200 = 0.77

<em>Since both np ≥ 10 and n(1-p) ≥ 10 </em>

<em>We can approximate this discrete binomial distribution with the continuous Normal distribution. As the sample size is large enough, not applying the continuity correction factor makes no significant  difference. </em>

The approximation would be to a Normal curve with this parameters:

<em>Mean </em>

p = 0.77

<em>Standard deviation </em>

\bf s=\sqrt{\frac{p(1-p)}{n}}=\sqrt{\frac{0.77*0.23}{200}}=0.0298

The 90% confidence interval for the proportion would be then  

\bf  [0.77-z^*0.0298, 0.77+z^*0.0298]

where \bf z^* is the 10% critical value for the Normal N(0,1) distribution , this is a value such that the area under the N(0,1) curve outside the interval \bf [-z^*,z^*] is 10%=0.1

We can either use a table, a calculator or a spreadsheet to get this value.

In Excel or OpenOffice Calc we use the function

<em>NORMSINV(0.95) and we get a value of 1.645 </em>

The 90% confidence interval for the proportion is then

\bf  [0.77-1.645^*0.0298, 0.77+1.645^*0.0298]=[0.7210,0.8189]

This means there is a 90% probability that the proportion of people who watch educational television is between 72.10% and 81.89%

If the television company wanted to publicize the proportion of viewers, do you think it should use the 90% confidence interval?

Yes, I do.

5 0
2 years ago
Other questions:
  • During the three weeks how many customers came from zones 3 and 4
    5·1 answer
  • A flour canister is 25 cm tall and has a diameter of 20 cm. It is filled to 3 cm from top. what volume of flour does it contain?
    5·1 answer
  • jay discounts a 100-day note for $25,000 at 13%. the effective rate of interest to the nearest hundredth percent is what %
    14·1 answer
  • 30 ones, 82 thousands, 4 hundred thousands, 60 tens and 100 hundreds. What number am i
    8·1 answer
  • Emma, Brandy, and Damian will cut a rope that is 29.8 feet long into 3 jump ropes. Each of the three jump ropes will be the same
    9·1 answer
  • C) Your parents have been advised to save 5% of their income for your college education
    10·2 answers
  • Candidate A is facing two opposing candidates in a mayoral election. In a recent poll of 300 residents, 98 supported candidate B
    12·1 answer
  • Which table shows a function that is decreasing over the interval (−2, 0)? A 2-column table with 4 rows. The first column is lab
    11·2 answers
  • Question<br> Find the multiplicative inverse of 0.13.
    6·1 answer
  • The function D(t) defines a traveler’s distance from home, in miles, as a function of time, in hours. Which times and distances
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!