MATHEMATICS COLLEGE

Cost of a dozen pens is ₹ 180 and cost of 8 ball pens is ₹ 56. Find the ratio of the cost of a pen to the cost of a ball pen. [1 ½ m]

Answers

Answer 1

Answer:

Answer:

Ratio of cost of a pen to cost of a ball pen is 15:7

Step-by-step explanation:

Given that:

Cost of dozen pens = ₹180

Unit rate = $(180)/(12)$

Unit rate = ₹ 15 per pen

Cost of 8 ball pens = ₹ 56

Unit rate = $(56)/(8)$

Unit rate = ₹7 per ball pen

Ratio of cost of a pen to cost of a ball pen,

15 : 7

Hence,

Ratio of cost of a pen to cost of a ball pen is 15:7

Related Questions

In a University of Wisconsin (UW) study about alcohol abuse among students, 100 of the 40,858 members of the student body in Madison were sampled and asked to complete a questionnaire. One question asked was, "On how many days in the past week did you consume at least one alcoholic drink?" a. Identify the population and the sample. b. For the 40,858 students at UW, one characteristic of interest was the percentage who would respond "zero" to this question. For the 100 students sampled, suppose 29% gave this response. Does this mean that 29% of the entire population of UW students would make this response? Explain.
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Which table represents the statement “An airplane is flying at a speed of 525 miles per hour “?
Niccola travels at an average speed of 40 mph for 50 miles.Without stopping, Niccola then travels 60 miles in 1.75 hours.Find her average speed for the entire journey to 2 dp.

Nielsen Media Research wants to estimate the mean amount of time, in minutes, that full-time college students spend texting each weekday.Find the sample size necessary to estimate that mean with a 15 minute margin of error. Assume that a 96% confidence level is desired and that the standard deviation is estimated to be 112.2 minutes.

Answers

Answer:

n=237

Step-by-step explanation:

Previous concepts

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

Assuming the X follows a normal distribution

$X \sim N(\mu, \sigma=112.2)$

We know that the margin of error for a confidence interval is given by:

$Me=z_(\alpha/2)(\sigma)/(√(n))$ (1)

The next step would be find the value of $\z_(\alpha/2)$ , $\alpha=1-0.96=0.04$ and $\alpha/2=0.02$

Using the normal standard table, excel or a calculator we see that:

$z_(\alpha/2)=2.054$

If we solve for n from formula (1) we got:

$√(n)=(z_(\alpha/2) \sigma)/(Me)$

$n=((z_(\alpha/2) \sigma)/(Me))^2$

And we have everything to replace into the formula:

$n=((2.054(112.2))/(15))^2 =236.05$

And if we round up the answer we see that the value of n to ensure the margin of error required $\pm=15 min$ is n=237.

Which events have a probability of 25 percent? Select three options.choosing a green jelly bean out of a bag that contains 2 green jelly beans, 1 red jelly bean, and 5 yellow jelly beans
rolling a number less than 3 on a six-sided die
spinning a number less than 2 on a spinner that has four equal sections numbered from 1 to 4
choosing an Oregon state quarter out a bag that contains 4 California state quarters, 3 Oregon state quarters, 6 Texas state quarters, and 3 New York state quarters
choosing a spade out of a standard deck of cards that contains 13 hearts, 13 clubs, 13 diamonds, and 13 spades

Answers

Choosing a green jelly bean.

Spinning a number less than 2 on a spinner.

Choosing a spade out of a standard deck of cards.

What are the probabilities?

Probability determines the chances that an event would happen. The probability the event occurs is 1 and the probability that the event does not occur is 0.

Probability of choosing a green jelly bean = number of green jelly bean / total number of beans

2/8 x 100 = 25%

Probability of spinning a number less than 2 on a spinner = number that is less than 2 / total number of sections

1/4 x 100 = 25%

Probability of choosing a choosing a spade= number of spade / total cards in the deck

13/54 x 100 = 25%

To learn more about probability, please check: brainly.com/question/13234031

The three options that have a probability of 25 percent are:

- Choosing a green jelly bean

- Spinning a number less than 2 on a spinner

- Choosing a spade from a standard deck of cards

The probability of an event occurring is calculated by dividing the number of favorable outcomes by the total number of possible outcomes. A probability of 25 percent corresponds to a ratio of 1 out of 4 (since 25% is one-fourth of 100%). Let's analyze the options:

1. Choosing a green jelly bean: There are 2 green jelly beans out of a total of 2 + 1 + 5 = 8 jelly beans. The probability is 2/8, which simplifies to 1/4 or 25%. This option has a probability of 25%.

2. Rolling a number less than 3 on a six-sided die: There are 2 favorable outcomes (1 and 2) out of 6 possible outcomes (1 through 6). The probability is 2/6, which simplifies to 1/3 or approximately 33.33%. This option does not have a probability of 25%.

3. Spinning a number less than 2 on a spinner: There is 1 favorable outcome (1) out of 4 possible outcomes (1 through 4). The probability is 1/4 or 25%. This option has a probability of 25%.

4. Choosing an Oregon state quarter: There are 3 Oregon state quarters out of a total of 4 + 3 + 6 + 3 = 16 state quarters. The probability is 3/16, which is not equal to 25%.

5. Choosing a spade from a standard deck of cards: There are 13 spades out of a total of 13 + 13 + 13 + 13 = 52 cards. The probability is 13/52, which simplifies to 1/4 or 25%. This option has a probability of 25%.

Learn more about probability here

brainly.com/question/32117953

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miranda is riding her bicycle she goes from 5m/s to 20m/s over a period of 30 seconds at. what rate what is her acceleration

Answers

Step-by-step explanation:

Acceleration= (final velocity - initial velocity)/ time

= v-u/t

v = 20m/s

u = 5m/s

t= 30s

= 20-5/30

= 15/30

= 0.5ms^-2

Let X1, X2, and X3 represent the times necessary to perform three successive repair tasks at a service facility. Suppose they are normal random variables with means of 50 minutes, 60 minutes, and 40 minutes, respectively. The standard deviations are 15 minutes, 20 minutes, and 10 minutes, respectively. a Suppose X1, X2, and X3 are independent. All three repairs must be completed on a given object. What is the mean and variance of the total repair time for this object.

Answers

Answer:

The mean of the total repair time is 150 minutes.

The variance of the total repair time is 725 minutes^2.

Step-by-step explanation:

To solve this problem, we have to use the properties of the mean and the variance. Our random variable is the sum of 3 normal variables.

In the case, for the mean, we have that the mean of the sum of 3 normal variables is equal to the sum of the mean of the 3 variables:

$y=x_1+x_2+x_3 \n\nE(y)=E(x_1+x_2+x_3)=E(x_1)+E(x_2)+E(x_3)\n\nE(y)=50+60+40=150$

For the variance, we apply the property for the sum of independent variables (the correlation between the variables is 0):

$V(y)=V(x_1)+V(x_2)+V(x_3)\n\nV(y)=s_1^2+s_2^2+s_3^2\n\nV(y)=15^2+20^2+10^2\n\nV(y)=225+400+100\n\nV(y)=725$

In the drawing, what is the measurment of angle y?

Answers

According to the vertical angle rule we know that x is 40 degrees. The sum of all angles in a triangle make 180, so the sum of x, 60, and the third angle is 180. x is 40 so the third angle is 180-60-40 which is 80 degrees. y is an adjacent angle, which means that the sum of y and 80 degrees is 180. 180-80 is 100, so y is 100 degrees.

What is the solution of the equation? 7y-4=9y+13-4y