All categories

3 years ago

A single card is drawn from a deck. Find the probability of selecting a heart or a 9

1 answer:

6 0

Probability of heart = 13/52
probability of nine = 4/52

you add the probability because of the word "or" but must subtract the probability of drawing the 9 hearts because it's counted twice. counted once in heart probability and once again in nine probability.

probability of 9 <3 = 1/52

probability of heart or nine:
13/52 + 4/52 - 1/52 = 16/52
simplified;
= 4/13

You might be interested in

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

Given: 3x+7+2(4x+1) = 3(x-1) -4 prove: x=-2

denis23 [38]

Answer:

x = -2, proven below.

Step-by-step explanation:

3x + 7 + 2(4x+1) = 3(x-1) - 4

3x + 7 + 8x + 2 = 3x - 3 - 4

9 + 11x = 3x - 7

16 + 11x = 3x

16 = - 8x

-2 = x

7 0

3 years ago

A lawyer charges for her services based on the number of hours worked. The expression gives the total cost for h hours is 200h+2

zhannawk [14.2K]

H is the number of hours worked. So the expression 200h+250 is 200 times the number of hours plus 250.

Here's a few computations using different values for h

1 hour --> (200)(1)+250 = 450
2 hours --> (200)(2) + 250 = 650
3 hours --> (200)(3)+250 = 850
10 hours --> (200)(10)+250 = 2250

As you can see the 250 is fixed. It gets added to the cost no matter how many hours the lawyer works. This is most likely a flat fee. Just to meet the lawyer you pay $250.

The 200 gets multiplied by the hours worked. So the 200 is an hourly rate. The more hours the lawyer works, the more he gets paid because this part of the expression depends on the hours worked.

Thus, an interpretation of the expression 200h + 250 is that the lawyer charges a fee of $250 per consultation and an additional $200 per hour on top of that.

4 0

3 years ago

What is the value of the expression?

gulaghasi [49]

The answer is fourteen

3 0

3 years ago

Make a table for each function rule. Then graph each equation using the points you created.

aleksandrvk [35]

Answer:

1.f(x)=2x-5

i will take the set {-2,-1,0,1,2}

f(-2)=2(-2)-5

=-4-5

=-9

f(-1)=2(-1)-5

=-2-5

=-7

f(0)=2(0)-5

=-5

f(1)=2(1)-5

=-3

f(2)=2(2)-5

=-1

so the coordinates of the function is {-9,-7,-5,-3,-1}

2.f(x)=-3x+6

i will the take the set {-2,-1,0,1,2} too

f(-2)=-3(-2)+6=6+6=12

f(-1)=-3(-1)+6=3+6=9

f(0)=-3(0)+6=6

f(1)=-3(1)+6=-3+6=3

f(2)=-3(2)+6=-6+6=0

{12,9,6,3,0}

3.f(x)=2/3.x+4

{-2,-1,0,1,2}

f(-2)=2/3(-2)+4=-4/3+4=(-4+12)/3=8/3

f(-1)=2/3(-1)+4=-2/3+4=(-2+12)/3=10/3

f(0)=2/3(0)+4=4

f(1)=2/3(1)+4=2/3+4=(2+12)/3=14/3

f(2)=2/3(2)+4=4/3+4=(4+12)/3=16/3

{8/3,10/3,4,14/3,16/3}

you're can graph those coordinates

actually you can take other coordinates...

CMIIW

7 0

2 years ago