All categories

2 years ago

22. Sammy walks home from school every day at a rate of 4 miles per hour. It takes him 30 minutes

1 answer:

8 0

Sammy walks at 4 miles an hour for half an hour. This means the walk is 2 miles in 30 minutes.

Candy is going 6 miles an hour, so it will only takes her 1/3 of an hour, or 20 minutes, to cover 2 miles.

So, Candy gets home 10 minutes faster (30-20) than Sammy.

You might be interested in

A painting class charges a $55 registration fee plus an additional $25 for each week that you attend. Write an equation that cou

lilavasa [31]

Answer:

y=25x+55

7 weeks = 230

gyhbgt

4 0

2 years ago

The given equation is either linear or equivalent to a linear equation. solve the equation. (if there is no solution, enter no s

murzikaleks [220]

2x+12=33
2x=21
x=10.5
The answer is 10.5

6 0

2 years ago

I need help this Question

Delicious77 [7]

Using the combination formula, it is found that the number of ways to choose the presenters is given by:

C. 462.

The order in which the presents are chosen is not important, hence the <em>combination formula</em> is used to solve this question.

<h3>What is the combination formula?</h3>

$C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by:

$C_{n,x} = \frac{n!}{x!(n-x)!}$

In this problem, 6 students are chosen from a set of 11, hence the number of ways is given by:

$C_{11,6} = \frac{11!}{6!5!} = 462$

More can be learned about the combination formula at brainly.com/question/25821700

#SPJ1

8 0

1 year ago

Can someone help me, please?

MrRa [10]

Answer:

For the first two you are right, the last two should be 1/10 and 9/10.

Step-by-step explanation:

The probability that you win is both blue and even number happen, which is 1/5 * 3/6 = 3/30 = 1/ 10, then the probability you not win is 1- 1/10 = 9/10.

If it is helpful, plz give me Brainliest.

7 0

2 years ago

A man travels 20 km by car from Town P to Town Q at an average speed of x km/h. He finds that the time of the journey would be s

yuradex [85]

Answer:

x = 20.

Step-by-step explanation:

First, you should remember the relation:

Distance = Speed*Time.

First, we know that a man travels a distance of 20km at a speed of x km/h, in a time T.

We can write this as:

20km = (x km/h)*T

We know that the time is shortened by 12 minutes if the speed is increased by 5km/h

Rewriting these 12 minutes in hours (remember that 60min = 1 hour)

12 min = (12/60) hours = 0.2 hours

Then from this, he can travel the same distance of 20km in a time T minus 0.2 hours if the speed is increased by 5 km/h

We can write this as:

20km = (x + 5 km/h)*(T - 0.2 h)

Then we have a system of two equations, and we want to find the value of x:

20km = (x km/h)*T

20km = (x + 5 km/h)*(T - 0.2 h)

First, we should isolate the variable T in one of the equations, if we isolate it in the first one, we will get:

20km/(x km/h) = T

Replacing that in the other equation we get:

20km = (x + 5 km/h)*(T - 0.2 h)

20km = (x + 5 km/h)*( 20km/(x km/h) - 0.2 h)

Now we can solve this for x.

Removing the units (that we know that are correct) so the math is easier to read, we get:

20 = (x + 5)*(20/x - 0.2)

We only want to solve this for x.

20 = x*20/x - x*0.2 + 5*20/x - 5*0.2

20 = 20 - 0.2*x + 100/x - 1

subtracting 20 in both sides we get:

20 - 20 = 20 - 0.2*x + 100/x - 1 - 20

0 = -0.2*x + 100/x - 1

If we multiply both sides by x we get:

0 = -0.2*x^2 + 100 - x

-0.2*x^2 - x + 100 = 0

This is just a quadratic equation, we can solve it using the Bhaskara's equation, the solutions are:

$x = \frac{-(-1) \pm \sqrt{(-1)^2 - 4*(-0.2)*100} }{2*-0.2} = \frac{1 \pm 9 }{-0.4}$

Then the two solutions are:

x = (1 + 9)/-0.4 = -25

x = (1 - 9)/-0.4 = 20

As x is used to represent a speed, the negative solution does not make sense, so we should use the positive one.

x = 20

then the average speed initially is 20 km/h

3 0

2 years ago