A box of light bulbs contains exactly 3 light bulbs that are defective. What is the probability that a sample of light bulbs picked at random from this box will contain at least 1 defective light bulb?
(1) The light bulbs in the sample will be picked 1 at a time without replacement.
(2) The sample will contain exactly 20 light bulbs.
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Probability

A box of light bulbs contains exactly 3 light bulbs that are defective. What is the probability that a sample of light bulbs picked at random from this box will contain at least 1 defective light bulb?
2 October 2023, by hurtado claudio 
In the town of Z, the town lion roars on some days and not on others. If a day is chosen at random from last March, what is the probability that on that day, either the town lion roared or it rained?
25 July 2022, by hurtado claudioIn the town of Z, the town lion roars on some days and not on others. If a day is chosen at random from last March, what is the probability that on that day, either the town lion roared or it rained?
(1) last March, the lion never roared on a rainy day.
(2) Last March, the lion roared on 10 fewer days than it rained. 
A box contains only red chips, white chips, and blue chips. If a chip is randomly selected from the box, what is the probability that the chip will be either white or blue?
25 July 2022, by hurtado claudioA box contains only red chips, white chips, and blue chips. If a chip is randomly selected from the box, what is the probability that the chip will be either white or blue?
(1) The probability that the chip will be blue is 1/5.
(2) The probability that the chip will be red is 1/3. 
A fish tank contains a number of fish, including 5 Fantails. If two fish are selected from the tank at random, what is the probability that both will be Fantails?
25 July 2022, by hurtado claudioA fish tank contains a number of fish, including 5 Fantails. If two fish are selected from the tank at random, what is the probability that both will be Fantails?
(1) The probability that the first fish chosen will be a Fantail is 1/2.
(2) If the first selected fish is a Fantail, then the probability the second selection is also a Fantail is 4/9 
A lottery is played by selecting X distinct single digit numbers from 0 to 9 at once such that order does not matter. What is the probability that a player will win playing the lottery?
25 July 2022, by hurtado claudioA lottery is played by selecting X distinct single digit numbers from 0 to 9 at once such that order does not matter. What is the probability that a player will win playing the lottery?
(1) Players must match at least two numbers with machine to win.
(2) X = 4 
In a certain game only one player can win and only one player always eventually wins. James, Austin, and Katelyn play this game together 3 times in a row. What is the probability that Katelyn wins at least one of the 3 games.?
25 July 2022, by hurtado claudioIn a certain game only one player can win and only one player always eventually wins. James, Austin, and Katelyn play this game together 3 times in a row. What is the probability that Katelyn wins at least one of the 3 games.?
(1) The probability that either James or Austin wins the game is 3/4
(2) James and Katelyn have an equal probability of winning the game. 
A pack of 12 cards contains either red or black cards. What is the probability that a card chosen at random will be a red card?
25 July 2022, by hurtado claudioA pack of 12 cards contains either red or black cards. What is the probability that a card chosen at random will be a red card?
(1) The pack has 6 more red cards than black cards
(2) The pack has 3 red cards for every black card 
A total of 20 interns and 15 fulltime employees work in the 35 offices of a company, with one person working in each office. One office is selected at random to get an upgraded desk. What is the probability that the office selected will be that of a female intern?
25 July 2022, by hurtado claudioA total of 20 interns and 15 fulltime employees work in the 35 offices of a company, with one person working in each office. One office is selected at random to get an upgraded desk. What is the probability that the office selected will be that of a female intern?
(1) Of the interns, 15 of them are female.
(2) Of the interns, 5 of them are male. 
A group of N students will be randomly seated in a row of N chairs. What is the probability that Beth, one of the students, will be at the extreme righthand end of the row?
25 July 2022, by hurtado claudioA group of N students will be randomly seated in a row of N chairs. What is the probability that Beth, one of the students, will be at the extreme righthand end of the row?
(1) N is an odd prime number
(2) the probability that Steve, another one of the students, is at the extreme lefthand end of the row is 1/13 
If there are 15 children in a gym class and 2 children are to be randomly chosen to perform a demonstration, how many of the children are lefthanded?
25 July 2022, by hurtado claudioIf there are 15 children in a gym class and 2 children are to be randomly chosen to perform a demonstration, how many of the children are lefthanded?
1) The probability of no lefthanded children being chosen is 3/7
2) The number of lefthanded children is less than the number of right handed children in the class