√1521 = evaluate 390²

A cyclist travels 20 miles in the same amount of time it takes a hiker to walk 6 miles. The rate of the cyclist is 7 mph faster

Anna11 [10]

Answer:

The speed of the cyclist is 10 miles per hour .

Step-by-step explanation:

Given as :

The distance cover by cyclist = $D_1$ = 20 miles

The distance cover by biker = $D_2$ = 6 miles

The speed of biker = $S_2$ = s mph

The speed of cyclist = $S_1$ = 7 + s mph

The time taken by both cyclist and biker = t hour

Now. Distance = Speed × Time

So, $D_1$ = $S_1$ × t

Or, 20 = s × t

Or, t = $\frac{20}{7+s}$ .....1

And ,

$D_2$ = $S_2$ × t

or, 6 = s t

Or, t = $\frac{6}{s}$ ....2

From Eq 1 and 2

I.e $\frac{20}{7+s}$ = $\frac{6}{s}$

Or, 20 s = 6 ( 7 + s )

Or, 20 s - 6 s = 42

Or, 14 s = 42

∴ s = $\frac{42}{14}$

I,e s = 3 miles per hour

So, The speed of biker = $S_2$ = s = 3 miles per hour

And The speed of cyclist = $S_1$ = 7 + s = 7 + 3= 10 miles per hour

Hence The speed of the cyclist is 10 miles per hour . Answer

4 0

3 years ago

Work out an expression, in terms of x, for the perimeter of the shape.<br> Simplify your answer.

sammy [17]

Answer:1+3x+9+x+8+2x= 6x+9

so =3(x+3)

Step-by-step explanation:

7 0

3 years ago

I bought a car of 650,000 and<br>sold it for 520,000. Find the<br>lost Percent ?<br>

Tom [10]

Answer:

20% decrease in value.

Step-by-step explanation:

Do 650,000 divided by 100 to find what 1% of the original price is:

650,000 divided by 100 = 6,500

To find what percentage of the original price 520,000 is, we divide it by 1% of the original cost (6,500):

520,000 divided by 6,500 = 80 (percent)

So if 520,000 is 80% of 650,000 the car has decreased in value by 20%.

7 0

3 years ago

A real estate agent has 14 properties that she shows. She feels that there is a 50% chance of selling any one property during a

Ratling [72]

Answer:

91.02% probability of selling more than 4 properties in one week.

Step-by-step explanation:

For each property, there are only two possible outcomes. Either it is sold, or it is not. The chance of selling any one property is independent of selling another property. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

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

And p is the probability of X happening.

In this problem we have that:

$n = 14, p = 0.5$

Compute the probability of selling more than 4 properties in one week.

Either you sell 4 or less properties in one week, or you sell more. The sum of the probabilities of these events is decimal 1. So

$P(X \leq 4) + P(X > 4) = 1$

We want to find $P(X > 4)$ . So

$P(X > 4) = 1 - P(X \leq 4)$

In which

$P(X \leq 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4)$

So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{14,0}.(0.5)^{0}.(0.5)^{14} = 0.000061$

$P(X = 1) = C_{14,1}.(0.5)^{1}.(0.5)^{13} = 0.000854$

$P(X = 2) = C_{14,2}.(0.5)^{2}.(0.5)^{12} = 0.0056$

$P(X = 3) = C_{14,3}.(0.5)^{3}.(0.5)^{11} = 0.0222$

$P(X = 4) = C_{14,4}.(0.5)^{4}.(0.5)^{10} = 0.0611$

So

$P(X \leq 4) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) = 0.000061 + 0.000854 + 0.0056 + 0.0222 + 0.0611 = 0.0898$

Finally

$P(X > 4) = 1 - P(X \leq 4) = 1 - 0.0898 = 0.9102$

91.02% probability of selling more than 4 properties in one week.

8 0

3 years ago

Jack invested $7,100 in an account paying an interest rate of

mars1129 [50]

Second one 3,3,8,3,8,3

8 0

3 years ago