Ask Me Help Desk - Probability math

1.There are 52 cards in a deck. There are 4 eights and 4 nines. What is the probability that if you cut the deck, you'll get an eight or a nine? Express your answer as a decimal number rounded to the hundredths place. Place a 0 to the left of the decimal point, and don't put any spaces in your answer.

2.There are 52 cards in a deck. There are 13 different cards in the deck that are clubs. What is the probability that if you cut the deck, you'll get a club? Express your answer as a percent. Include the percent sign at the end of your number, and don't put any spaces in your answer.

3. There are 6 numbers on a normal dice. What is the probability that if you roll the dice, you'll get a 5 or a 6? Express your answer as a fraction with no spaces. Reduce the fraction to its simplest form.

4. There are 6 numbers on a normal dice. What is the probability that if you roll the dice, you'll get an odd number? Express your answer as a percent. Include the percent sign at the end of your number, and don't put any spaces in your answer.

1. There are 8 possibilities: 4 eights and 4 nines. There are a total of 8 possibilities. The answer is 8/52. You divide the number that fit the problem by the total number of cards (the total of all possibilities). You can reduce that to 2/13. This is how you do all of these problems.

2. You do that the same way. How many clubs? Divide the number of clubs by the total number of cards. Since they want it as a percentage, multiply that number by 100%.

3. There are 6 sides to a dice. You want two of them. So, the answer is the number that are "ok" divided by the total number possible. You try it. If you have trouble, I'll give you some more hints.

4. How many odd numbers on a dice. How many total numbers on a dice? Divide the number of odd numbers by the number of total numbers. Multiply the answer by 100% and follow the problem's directions.

Now, you give it a try and report back.

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Originally Posted by Perito

1. There are 8 possibilities: 4 eights and 4 nines. There are a total of 8 possibilities. The answer is 8/52. You divide the number that fit the problem by the total number of cards (the total of all possibilities). You can reduce that to 2/13. This is how you do all of these problems.

2. You do that the same way. How many clubs? Divide the number of clubs by the total number of cards. Since they want it as a percentage, multiply that number by 100%.

3. There are 6 sides to a dice. You want two of them. So, the answer is the number that are "ok" divided by the total number possible. You try it. If you have trouble, I'll give you some more hints.

4. How many odd numbers on a dice. How many total numbers on a dice? Divide the number of odd numbers by the number of total numbers. Multiply the answer by 100% and follow the problem's directions.

Now, you give it a try and report back.

Okay I'm still confused:confused:

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1.There are 52 cards in a deck. There are 4 eights and 4 nines. What is the probability that if you cut the deck, you'll get an eight or a nine? Express your answer as a decimal number rounded to the hundredths place. Place a 0 to the left of the decimal point, and don't put any spaces in your answer.

There are 4 eights and 4 nines. There are, therefore, 8 ways that you can pick either an 8 or a 9. There are 52 cards.

$Probability\,of\,8\,or\,9=\frac {8}{52}=\frac {2}{13}$

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2.There are 52 cards in a deck. There are 13 different cards in the deck that are clubs. What is the probability that if you cut the deck, you'll get a club? Express your answer as a percent. Include the percent sign at the end of your number, and don't put any spaces in your answer.

13 cards are clubs. 52 cards total

$Probability\,of\,club=\frac {13}{52} = \frac 14$

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3. There are 6 numbers on a normal dice. What is the probability that if you roll the dice, you'll get a 5 or a 6? Express your answer as a fraction with no spaces. Reduce the fraction to its simplest form.

There is 1 5 on a dice and 1 six on a dice. There are two possibilities out of 6

$Probability\,of\,5\,OR\,6\,in\,1\,roll\,of\,the\,d ice\,=\,\frac {1}{6}$

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4. There are 6 numbers on a normal dice. What is the probability that if you roll the dice, you'll get an odd number? Express your answer as a percent. Include the percent sign at the end of your number, and don't put any spaces in your answer.

There are three odd numbers on a dice: 1, 3, and 5

$Probability\,of\,odd\,number\,in\,1\,roll\,of\,the \,dice\,=\,\frac {3}{6}\,=\,\frac 12$