Question 180539This question is from textbook Chapter 11 Skill practice
: Can you explain these problem?
1.) When text messaging on a telephone, pressing a 3 types D, E, F, or 3. Pressing a 7 types P, Q, R, S, or 7. How many messages are possible by pressing a 3, a 7, and then a 3?
11.) What is the probability that a random 2-digit number is a multiple of 7?
13.) A mother is making different lunches for each of her 3 children. If each child grabs a lunch bag at random, what is the probability that all 3 children will get the correct bag?
21.) Two number cubes are rolled--one blue and one yellow. Find the probability that the yellow cube is even, and the sum is 7. Explain why the events are dependent.
Please answer me as soon as you could. Thank you for your help.
This question is from textbook Chapter 11 Skill practice
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! 1.) When text messaging on a telephone, pressing a 3 types D, E, F, or 3. Pressing a 7 types P, Q, R, S, or 7. How many messages are possible by pressing a 3, a 7, and then a 3?
Ans: 3*4*3 = 36
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11.) What is the probability that a random 2-digit number is a multiple of 7?
Ans: There are 99 2-digit numbers if you do not include 00.
Multiples of 7 are: 7,14,21,28,35,42,49,etc, 98
So there are 14 multiples of 7 that are 2-digit numbers
Ans: Probability = 14/99
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13.) A mother is making different lunches for each of her 3 children. If each child grabs a lunch bag at random, what is the probability that all 3 children will get the correct bag?
Ans: There are 3!=6 possible ways to pick the bags; only 1 is the right way.
Probability = 1/6
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21.) Two number cubes are rolled--one blue and one yellow. Find the probability that the yellow cube is even, and the sum is 7.
(yellow is even and sum is 7) = (2,5), (4,3), (6,1)-------3 elements
Total number of outcomes: 6*6 = 36
Probability(yellow even and sum is 7) = 3/36 = 1/12
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Explain why the events are dependent.
I'll leave that to you.
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Cheers,
Stan H.
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