Question

There is a 20% chance that it will snow on Monday and a 40% chance on Tuesday. What is the probability that it will NOT snow on both Monday and Tuesday?

Answer 1

. Solve: 5x < 9x-1 / 2 

-4x < - 1/2 , now divide by -4 and switch signs 

x > 1/8 


2. There is a 20% chance that it will snow on Monday and a 40% chance on Tuesday. What is the probability that it will NOT snow on both Monday and Tuesday? 

P( NOT snow on both Monday and Tuesday) = (1-.2)(1-.4) = 12/25 

c. 12/25 


3. The total cost of renting a sailboat is $120 plus $60 a day. How many days was a sailboat rented if the total cost was $360? Solve. 

120 + 60d = 360 

60d = 360 - 120 = 240 

d = 4 



4. Two cards are chosen at random without replacement from a deck of 52 cards containing 4 kings. Which expression could be used to find the probability of choosing two kings? 

b. 4/52 x 3/51 

There are 4 x 3 ways to pick 2 kings 

There are 52 x 51 ways to pick any two cards

Answer 2

P(Event) = 4/5 * 3/5 = 12/25

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Y=Yes=Will Snow

N=No=Won't Snow

There is a 20% chance (1/5) that it will snow on Monday. This means that there is an 80% (4/5) chance that it won't snow on Monday.

Y, N, N, N, N

There is a 40% chance (2/5) that it will snow on Tuesday. This means that there is a 60% chance (3/5) that it won't snow on Tuesday.

Y, Y, N, N, N

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Create a table for combinations N, N or Y, N or N, Y or Y, Y:

*Where N, N place (X). Where Y, N or N, Y or Y, Y - place (O).

   : Y  N  N  N  N
.................................
Y : O  O  O  O O
Y : O  O  O  O O
N : O  X  X  X  X
N : O  X  X  X  X
N : O  X  X  X  X

The combination N, N represented with (X) appears 12 times out of 25 which is your answer (12/25).