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Illusion [34]
3 years ago
6

Please help. I don't understand ​

Mathematics
1 answer:
pashok25 [27]3 years ago
7 0

Answer:

∠ACB = 72

Step-by-step explanation:

OAD is straight line.

∠DAB +  ∠OAB  = 180

142 + ∠OAB  = 180

          ∠OAB = 180 - 142

          ∠OAB =  38

ΔAOB is isosceles triangle. OA = OB = radius

∠OAB = ∠OBA = 38   {angles opposite to equal sides or equal}

In ΔAOB ,

∠OAB + ∠OBA + ∠AOB = 180   {Anlge sum property of triangle}

   38 + 38 + ∠AOB = 180

               76 + ∠AOB = 180

                       ∠AOB = 180 - 76

                       ∠AOB = 104

THe angle subtended by an arc of a circle at the center is double the angle subtended by it at any point on the remaining part of the circle

∠AOB =  2*∠ACB

∠ACB = ∠AOB/2

         = 104/2

∠ACB = 72

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Rzqust [24]

Answer:

a. the probability of picking a navy sock and a black sock = P (A & B)

= (8/13 ) * (5/12) = 40/156 = 0.256

b. the probability of picking two navy or two black is

= 56/156 + 20/156 = 76/156 = 0.487

c. the probability of either 2 navy socks is picked or one black  & one navy socks.

= 40/156 + 56/156 = 96/156 = 0.615

Step-by-step explanation:

A sock drawer contains 8 navy blue socks and 5 black socks with no other socks.

If you reach in the drawer and take two socks without looking and without replacement, what is the probability that:  

Solution:

total socks = N = 8 + 5 + 0 = 13

a) you will pick a navy sock and a black sock?

Let A be the probability of picking a navy socks first.

Then P (A) = 8/13

without replacing the navy sock, will pick the black sock, total number of socks left is 12.

Let B be the probability of picking a black sock again.

 P (B) = 5/12.

Then, the probability of picking a navy sock and a black sock = P (A & B)

= (8/13 ) * (5/12) = 40/156 = 0.256

b) the colors of the two socks will match?

Let A be the probability of picking a navy socks first.

Then P (A) = 8/13

without replacing the navy sock, will pick another navy sock, total number of socks left is 12.

Let B be the probability of another navy sock again.

 P (B) = 7/12.

Then, the probability of picking 2 navy sock = P (A & B)

= (8/13 ) * (7/12) = 56/156 = 0.359

Let D be the probability of picking a black socks first.

Then P (D) = 5/13

without replacing the black sock, will pick another black sock, total number of socks left is 12.

Let E be the probability of another black sock again.

 P (E) = 4/12.

Then, the probability of picking 2 black sock = P (D & E)

= (5/13 ) * (4/12) = 5/39 = 0.128

Now, the probability of picking two navy or two black is

= 56/156 + 20/156 = 76/156 = 0.487

c) at least one navy sock will be selected?

this means, is either you pick one navy sock and one black or two navy socks.

so, if you will pick a navy sock and a black sock, the probability of picking a navy sock and a black sock = P (A & B)

= (8/13 ) * (5/12) = 40/156 = 0.256

also, if you will pick 2 navy sock, Then, the probability of picking 2 navy sock = P (A & B)

= (8/13 ) * (7/12) = 56/156 = 0.359

now either 2 navy socks is picked or one black  one navy socks.

= 40/156 + 56/156 = 96/156 = 0.615

4 0
2 years ago
The cost of six hens and one duck at the university poultry farm is GH₵40. While four hens and three ducks cost GH₵36. What is t
Anon25 [30]

Answer:

Step-by-step explanation:

Let's call hens h and ducks d. The first algebraic equation says that 6 hens (6h) plus (+) 1 duck (1d) cost (=) 40.

The second algebraic equations says that 4 hens (4h) plus (+) 3 ducks (3d) cost (=) 36.

The system is

6h + 1d = 40

4h + 3d = 36

The best way to go about this is to solve it by substitution since we have a 1d in the first equation. We will solve that equation for d since that makes the most sense algebraically. Doing that,

1d = 40 - 6h.

Now that we know what d equals, we can sub it into the second equation where we see a d. In order,

4h + 3d = 36 becomes

4h + 3(40 - 6h) = 36 and then simplify. By substituting into the second equation we eliminated one of the variables. You can only have 1 unknown in a single equation, and now we do!

4h + 120 - 18h = 36 and

-14h = -84 so

h = 6.

That means that each hen costs $6. Since the cost of a duck is found in the bold print equation above, we will sub in a 6 for h to solve for d:

1d = 40 - 6(6) and

d = 40 - 36 so

d = 4.

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