All categories

3 years ago

Q3. Kylie sits two maths test. She scores 19/25 in the first one, and 16/20 in the second one.

Mathematics

2 answers:

Rina8888 [55]3 years ago

7 0

She done better at the 2nd test because she only got 4 wrong but on the first test she got 6 wrong.

prohojiy [21]3 years ago

3 0

Answer: Kylie did better in the second one than she did in the first one

Step-by-step explanation:

If you do 19 divided by 25 you will get 0.76 so she got a 76% on the first test. Then if you do 16 divided by 20 you will get 0.8 so she got a 80% on the second test.

You might be interested in

Select the best definitions of population and sample. A sample is the group from whom information is being collected. A populati

Elena L [17]

Answer:

A population is defined as the data set which consists of all members of a specified group and the sample contains a part or a subset of a population.

For example : all the students of a school are population. But out of all, how many students play sports is a sample.

Hence, the answer is - A population is the complete group under study. A sample is the sub-collection of members of the population from which data are actually collected.

4 0

3 years ago

Find equations of the spheres with center(3, −4, 5) that touch the following planes.a. xy-plane b. yz- plane c. xz-plane

postnew [5]

Answer:

(a) (x - 3)² + (y + 4)² + (z - 5)² = 25

(b) (x - 3)² + (y + 4)² + (z - 5)² = 9

Step-by-step explanation:

The equation of a sphere is given by:

(x - x₀)² + (y - y₀)² + (z - z₀)² = r² ---------------(i)

Where;

(x₀, y₀, z₀) is the center of the sphere

r is the radius of the sphere

Given:

Sphere centered at (3, -4, 5)

=> (x₀, y₀, z₀) = (3, -4, 5)

(a) To get the equation of the sphere when it touches the xy-plane, we do the following:

i. Since the sphere touches the xy-plane, it means the z-component of its centre is 0.

Therefore, we have the sphere now centered at (3, -4, 0).

Using the distance formula, we can get the distance d, between the initial points (3, -4, 5) and the new points (3, -4, 0) as follows;

$d = \sqrt{(3-3)^2+ (-4 - (-4))^2 + (0-5)^2}$

$d = \sqrt{(3-3)^2+ (-4 + 4)^2 + (0-5)^2}$

$d = \sqrt{(0)^2+ (0)^2 + (-5)^2}$

$d = \sqrt{(25)}$

d = 5

This distance is the radius of the sphere at that point. i.e r = 5

Now substitute this value r = 5 into the general equation of a sphere given in equation (i) above as follows;

(x - 3)² + (y - (-4))² + (z - 5)² = 5²

(x - 3)² + (y + 4)² + (z - 5)² = 25

Therefore, the equation of the sphere when it touches the xy plane is:

(x - 3)² + (y + 4)² + (z - 5)² = 25

(b) To get the equation of the sphere when it touches the yz-plane, we do the following:

i. Since the sphere touches the yz-plane, it means the x-component of its centre is 0.

Therefore, we have the sphere now centered at (0, -4, 5).

Using the distance formula, we can get the distance d, between the initial points (3, -4, 5) and the new points (0, -4, 5) as follows;

$d = \sqrt{(0-3)^2+ (-4 - (-4))^2 + (5-5)^2}$

$d = \sqrt{(-3)^2+ (-4 + 4)^2 + (5-5)^2}$

$d = \sqrt{(-3)^2 + (0)^2+ (0)^2}$

$d = \sqrt{(9)}$

d = 3

This distance is the radius of the sphere at that point. i.e r = 3

Now substitute this value r = 3 into the general equation of a sphere given in equation (i) above as follows;

(x - 3)² + (y - (-4))² + (z - 5)² = 3²

(x - 3)² + (y + 4)² + (z - 5)² = 9

Therefore, the equation of the sphere when it touches the yz plane is:

(x - 3)² + (y + 4)² + (z - 5)² = 9

(b) To get the equation of the sphere when it touches the xz-plane, we do the following:

i. Since the sphere touches the xz-plane, it means the y-component of its centre is 0.

Therefore, we have the sphere now centered at (3, 0, 5).

Using the distance formula, we can get the distance d, between the initial points (3, -4, 5) and the new points (3, 0, 5) as follows;

$d = \sqrt{(3-3)^2+ (0 - (-4))^2 + (5-5)^2}$

$d = \sqrt{(3-3)^2+ (0+4)^2 + (5-5)^2}$

$d = \sqrt{(0)^2 + (4)^2+ (0)^2}$

$d = \sqrt{(16)}$

d = 4

This distance is the radius of the sphere at that point. i.e r = 4

Now substitute this value r = 4 into the general equation of a sphere given in equation (i) above as follows;

(x - 3)² + (y - (-4))² + (z - 5)² = 4²

(x - 3)² + (y + 4)² + (z - 5)² = 16

Therefore, the equation of the sphere when it touches the xz plane is:

(x - 3)² + (y + 4)² + (z - 5)² = 16

3 0

3 years ago

Change 225° to radian measure in terms of pi

a_sh-v [17]

Answer:

$\frac{5\pi }{4}$

Step-by-step explanation:

To convert from degree to radian measure

radian measure = degree measure × $\frac{\pi }{180}$

Hence

radian measure = 225 × $\frac{\pi }{180}$ = $\frac{225\pi }{180}$ = $\frac{5\pi }{4}$

5 0

3 years ago

Mike's age is five more than three times his sister's age. Mike is seventeen years old.

Agata [3.3K]

3x+5=17 that's the answer

7 0

3 years ago

Read 2 more answers

You plan to go skiing this weekend in Tennessee. The ski resort charges $18.50 per hour in addition to a $100 deposit to rent sk

Rina8888 [55]

Answer:

Part a) $y=18.50x+100$

Part b) The total cost is $\$220.25$

Part c) see the explanation

Step-by-step explanation:

Part a) Write a linear equation to represent this situation

Define the variables

Let

x ----> the number of hours

y ----> the total cost in dollars

we know that

The linear equation in slope intercept form is equal to

$y=mx+b$

where

m is the slope or the unit rate

b is the y-intercept or initial value (value of y when the value of x is equal to zero)

In this problem we have that

The unit rate or slope is equal to

$m=\$18.50\ per\ hour$

The y-intercept or initial value is equal to

$b=\$100$

substitute

$y=18.50x+100$

Part b) Use the equation to find the total cost to rent skis from 8:30 am to 3:00 pm

Remember that

3:00 pm=15:00

from 8:30 am to 3:00 pm, the total hours is equal to

15:00 -8:30=6:30=6.5 h

For x=6.5 h

substitute in the linear equation and solve for y

$y=18.50(6.5)+100\\y=\$220.25$

Part c) What does your answer mean in context of the problem?

we have that

y=220.25

That means -----> The total cost to rent skis for 6.5 hours is equal to $220.25

8 0

3 years ago