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3 years ago

I need help on 15 please

Mathematics

1 answer:

Nikolay [14]3 years ago

4 0

The ratio 12:20 because you need it to be equal to 3:5. 3 times 4 which makes 12 so you need to multiply 5 with 4 too

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Charlie is at an amusement park that has 18 different rides. Each ride costs $1.75. The function C(r) = 1.75r represents the tot

sleet_krkn [62]

Domain= [0,18], Range = [0,31.50]
If Charlie will only go to a single ride one time the possible rides he could go on would be 0 rides to all 18 rides for a domain of [0,18]. The output of the maximum and minimum x values would give us 0 dollars for riding 0 rides and 31.50 for riding all 18 (1.75 *0 = 0) and (1.75*18 = 31.50) so the range is [0, 31.50]

4 0

3 years ago

A high school mathematics teacher can grade a set of exams in 7 hours working alone. If their student teacher helps them, it wi

Stels [109]

It takes 9 hrs 19.8 minutes for the student teacher to grade the exams if they worked alone

Solution:

Let the efficiency of the school teacher be “x” and the efficiency of the student teacher be “y”

Here the word efficiency means the rate of doing work

Let the total work to be completed be W

According to the question,

The time taken by the school teacher to complete the work is 7 hrs.

So we can write it in equation form

$W = x \times 7$ ---- eqn 1

where W is the total work and x is the efficiency

Similarly for student teacher and school teacher doing the work simultaneously, we can write the equation as

$W =(x +y ) \times 4$

Equating eqn 1 and 2

$x \times 7=(x+y) \times 4$

7x = 4x + 4y

3x = 4y

So in ratio x : y = 4 : 3

Now putting value of x = 4 in equation (1) we get total work to be 28

Now, total time taken by the student teacher = total work ÷ efficiency of student teacher

Hence, total time taken by the student teacher = 28 ÷ 3 = 9.33 hrs

= 9 hrs 19.8 minutes

Hence it takes 9 hrs 19.8 minutes for the student teacher to grade the exams if they worked alone

4 0

3 years ago

help Pls no joking around

garri49 [273]

Answer:

I think like expressions you use x or y or such many variables. you use - or + too. like (x+2)y there are parentheses too.

8 0

2 years ago

Very confused especially on number three.

kogti [31]

Answer:

yes it was so confused for me too

5 0

3 years ago

3 people work full time together on a project, but their total time on the project is to be equivalent to only 1 person working

NikAS [45]

Let x = the amount of time that the third person needs to work on the job to add up to one

1 = 1/2 + 1/3 + x

1 - 1/2 - 1/3 = x

To subtract the fractions we need to put them all over a common denominator. Let's use 3*2 = 6 as the denominator; so 1 = 6/6, 1/2 = 3/6, 1/3 = 2/6:

6/6 - 3/6 - 2/6 = x

1/6 = x

The third person must work 1/6 time on the project.

3 0

3 years ago