The counting principle, and are these events independent?
Grade 9 Math Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
Luz's outfit is a top (one of 6 shirts or 4 sweaters) in one of 3 colors, plus a bag (one of 5 backpacks or 2 totes). How many different outfits are possible?
Jun's school has 12 students in drama and 9 in band. 5 of them are in both. How many students are in drama or band?
Pia's 3-digit code uses digits 0 to 9, with no digit used twice. The first digit is not 0 and the last digit is odd. How many codes are possible?
A 4-letter code uses the letters A to H, with no letter used twice and no vowels (A and E) allowed. Ren counts the codes. How many are possible?
Tala lines up 5 kids for a photo. Zee must stand first or last. In how many different orders can the kids line up?
A club with n members picks a president and a different treasurer, and has 132 ways to do it. How many members does Bo's club have?
A race gives gold, silver and bronze to three different runners out of n runners. There are 210 ways to give the medals. How many runners are in Esme's race?
At Milo's school, events A and B are independent. P(A) = p, P(B) = p + 0.2, and P(A and B) = 0.15. What is P(A), as a fraction in simplest form?
At Noah's school, events A and B are independent. The chance A does not happen is 2/5, and P(A and B) = 3/10. What is P(B), in simplest form?
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Two-way table of 150 students. Owns a bike and a skateboard: 45. Owns a bike, no skateboard: 45. No bike, owns a skateboard: 15. No bike, no skateboard: 45.
Kira surveyed 150 students and made the two-way table. A is “owns a bike” and B is “owns a skateboard”. For a random student, are A and B independent?
- Independent: 90/150 and 60/150 are close to each other
- Independent: bikes and skateboards are different things
- Independent: half of bike owners own a skateboard, so about half of the group does
- Not independent: 90/150 × 60/150 = 36/150, but 45/150 are in both