All categories

3 years ago

Kevin runs 8 miles in 84 minutes. At the same rate, how many minutes would he take to run 6 miles?

Mathematics

1 answer:

netineya [11]3 years ago

3 0

Kevin runs:

8 miles -- 84 minutes;

6 miles -- x minutes.

Write a proportion:

$\dfrac{8}{6}=\dfrac{84}{x}.$

Then $8\cdox =6\cdot 84,\\ \\x=\dfrac{6\cdot 84}{8}=3\cdot 21=63\ minutes.$

Answer: it takes him 63 minutes to run 6 miles

You might be interested in

The half-life of radium is 1690 years. If 20 grams are present now, how much will be present in 250 years?

Aneli [31]

Answer:

18.05 g

Step-by-step explanation:

The multiplier of the initial quantity is ...

(1/2)^(t/1690)

so, for t=250, this becomes ...

(1/2)^(250/1690) ≈ 0.902545

Then the quantity remaining of the initial 20 g is ...

(20 g)(0.902545) ≈ 18.05 g

3 0

3 years ago

Hector had 30 minutes to do a three-problem quiz. He spent 11 3 4 minutes on question A and 6 1 2 minutes on question B. How muc

stich3 [128]

Answer:

$11 \frac{3}{4}$ min

Step-by-step explanation:

In order to solve this problem, we must subtract the times he has already used from the time he has available, so we get:

$30-11 \frac{3}{4} - 6 \frac{1}{2}$

we can start solving this subtraction by turning all of the numbers into improper fractions so we get:

$\frac{30}{1}-\frac{11*4+3}{4}- \frac{6*2+1}{2}$

$\frac{30}{1}-\frac{47}{4}- \frac{13}{2}$

next, we can find a least common denominator. In this case it will be 4, so we need to turn all denominators into a 4, so we get:

$\frac{30*4}{1*4}-\frac{47}{4}- \frac{13*2}{2*2}$

$\frac{120}{4}-\frac{47}{4}- \frac{26}{4}$

and now we can subtract the numerators and copy the denominators so we get:

$\frac{120-47-26}{4}$

$\frac{47}{4}$

which can now be turned into a mixed number by dividing 47/4 which yields 11 with a remainder of 3, so the mixed number is:

$11 \frac{3}{4}$ min

and this is the amount of time he has available to solve the las problem.

6 0

3 years ago

Please help me out with this please!!

Monica [59]

It will be close to 15 days but don’t take my word for it

5 0

3 years ago

Plss help me quickly tyyy<br>either question 5 or six cus I need the explanation:)))

ozzi

Find FM using Pythagoras Theorem:

We're not after c^2 using pythag - rearrange it:

It don't matter were the B or A is in the equation - it'll give u the missing length you're after.

c^2 - b^2 = a^2

8^2 - 5^2 = a^2

Square root both sides to get A on its own

A= root 8^2 - 5^2

= root 39

= 6.24499....

6.24cm, but FM is root 39 I'll use throughout, even if I use 6.24 in calculations, it's to make things clearer for you.

Create diagonal line from B to E - drawing right-angle triangle A to B to E back to A.

AB is 16cm

AE is 8cm - given above

(because the triangle at the front & back are the same.)

Use Pythagoras Theorem for length BE:

a^2 + b^2 = c^2

16^2 + 8^2 = c^2

Square root

C = root 16^2 + 8^2

= 8 root 5

= 17.8885...

8 Square root 5 - I'll use for BE

Creat another triangle to find the angel -

B to E to (M between the length AD)

However, diagonal line B to M needed.

So, m is the mid-point of the base triangle, pretend to slice it in half from point M - this creates a mini rectangle. (ABM to MA - with M on side AD)

Now use this to find B to M:

(if MC is 5cm, BM is 5cm - on length BC)

C = root 16^2 + 5^2

= root 281

= 16.76305...

= 16.76

Create right-angle triangle:

Be to M back to B

BE= 8 root 5

EM = root 39

MB = root 281

So, the angle will be from EB to M.

EB is the hypotenuse

BM is the adjacent

AH means Cah, but the inverse

Cos-1(a/h)

Cos-1(root 281 / 8 root5) = 20.4326...

Thus, angle we're after is 20.43 degrees to 2.dp

(The easiest way for me to explain - it took a while)

Hope this helps!

4 0

2 years ago

I NEED HELP PLEASE! :)<br> thanks!

BigorU [14]

Add all the chips to find the total amount.

7 + 9 + 3 + 6 = 25 chips

Since there are 6 blue chips (6/25), that's the probability of just getting once.

When you pick a blue chip and it doesn't get replaced, then that means there is one fewer blue chip and one fewer from the total amount.

5/24

Multiply both probabilities.

6/25 * 5/24 = 30/600

Simplify.

30/600 → 1/20

Therefore, the answer is B

Best of Luck!

7 0

3 years ago