Joey earned $10 for every car he washed on Friday. If he earned $190, how many cars did he wash?

The Lopez family and the Russell family each used their sprinklers last summer. The water output rate for the Lopez family's spr

grin007 [14]

L = hours used by the Lopez's sprinkler

R = hours used by the Russell's sprinkler

so, we know the Lopez's sprinkler uses 15 Liters per hour, so say after 1 hour it has used 15(1), after 2 hours it has used 15(2), after 3 hours it has used 15(3) liters and after L hours it has used then 15(L) or 15L.

likewise, the Russell's sprinkler, after R hours it has used 40R, since it uses 40 Liters per hour.

we know that both sprinklers combined went on and on for 45 hours, therefore whatever L and R are, L + R = 45.

we also know that the output on those 45 hours was 1050 Liters, therefore, we know that 15L + 40R = 1050.

$\bf \begin{cases}
L+R=45\implies \boxed{L}=45-R\\
15L+40R=1050\\
----------\\
15\left(\boxed{45-R} \right)+40R=1050
\end{cases}
\\\\\\
675-15R+40R=1050\implies 25R=375\implies R=\cfrac{375}{25}\\\\\\ R=15$

how long was the Lopez's on for? well, L = 45 - R.

7 0

3 years ago

When Jill woke up, the temperature was -3 C. By noon the temperature had increased by 8 C.

AlekseyPX

-3+8.

We know that the temperature /was/ -3, so it was 3 under zero. It has /risen/ by 8, meaning we have added 8 degrees to whatever the starting temperature was.

We can find out how much the temperature is right now: it was -3, went through -2, -1, 0, 1, 2, 3, 4, and now its at 5 degrees. Thats risen by 8 degrees, right? And -3+8 is the same as 8-3 (commutative property of addition, since we basically did 8+(-3)) which equals 5, so we know that we got the correct answer. :)

3 0

3 years ago

A right circular cone of radius 6 inches, side length of 16 inches and height of h inches. Which is closest to the height of a c

Elis [28]

Answer:

Height of cone (h) = 14.8 in (Approx)

Step-by-step explanation:

Given:

Radius of cone (r) = 6 in

Slant height (l) = 16 in

Find:

Height of cone (h) = ?

Computation:

Height of cone (h) = √ l² - r²

Height of cone (h) = √ 16² - 6²

Height of cone (h) = √ 256 - 36

Height of cone (h) = √220

Height of cone (h) = 14.832

Height of cone (h) = 14.8 in (Approx)

8 0

2 years ago

Helen's house is located on a rectangular lot that is1 1-8 miles by 9/10 mile.Estimate the distance around the lot

klemol [59]

Answer: The distance around the lot is given by

$4\frac{1}{20}\ miles$

Step-by-step explanation:

Since we have given that

Length of rectangular lot is given by

$1\frac{1}{8}\\\\=\frac{9}{8}\ miles$

Width of rectangular lot is given by

$\frac{9}{10}\ mile$

We need to find the distance around the lot.

As we know the formula for "Perimeter of rectangle":

$Perimeter=2(Length+Width)\\\\Perimeter=2(\frac{9}{8}+\frac{9}{10})\\\\Perimeter=2(\frac{45+36}{40})\\\\Perimeter=2\times \frac{81}{40}\\\\Perimeter=\frac{81}{20}\\\\Perimeter=4\frac{1}{20}\ miles$

Hence, the distance around the lot is given by

$4\frac{1}{20}\ miles$

3 0

3 years ago

Read 2 more answers

For two events and , the probability that occurs is 0.8, the probability that occurs is 0.4, and the probability that both occur

sergey [27]

Answer:

P(B|A)=0.25 , P(A|B) =0.5

Step-by-step explanation:

The question provides the following data:

P(A)= 0.8

P(B)= 0.4

P(A∩B) = 0.2

Since the question does not mention which of the conditional probabilities need to be found out, I will show the working to calculate both of them.

To calculate the probability that event B will occur given that A has already occurred (P(B|A) is read as the probability of event B given A) can be calculated as:

P(B|A) = P(A∩B)/P(A)

= (0.2) / (0.8)

P(B|A)=0.25

To calculate the probability that event A will occur given that B has already occurred (P(A|B) is read as the probability of event A given B) can be calculated as:

P(A|B) = P(A∩B)/P(B)

= (0.2)/(0.4)

P(A|B) =0.5

7 0

3 years ago