817 Math Blog

Today in class we did more probabily work sheets for tomorrow's test. We got text books with probability problems in it. Here are three of the problems that we did in class.


3. A spinner has 2 congruent sectors coloured blue and green. The pointer is spun once, and a coin is tossed.

Find the probability of each events

a) blue and tails

b) blue or green and heads.

To find the total possible outcomes, you multiply the possible out comes of both together. The TPO for this problem is 4 (2x2=4)

To solve this problem, I started by making a probability tree.

The answer to a) is 1/4. 1/4 = 0.25. 0.25x100 = 25%

The probability of getting a blue and tails, is 25%.

The answer to b) is 2/4 = 1/2 = 0.5. 0.5x100 = 50%

The probability of getting a blue or green, and a heads is 50%.

4. Stanley has two sets of three cards face down on a table. Each se contains: the 2 of hearts, 5 of diamonds, and the 8 of clubs. He randomly turns over one card from each set.

Find the probability of each events:

a) Both cards are Red

b) The first card is Red and the second card is black.

c) Both cards are even numbers.

d) The sum of the numbers is greater than 8

The total possible outcomes for this problem is 9 (3x3=9)

For this problem, I also started out with a probability tree.

The answer to a) is 4/9 = 0.44. 0.44x100=44.4%

The answer to b) is 2/9 = 0.22. 0.22x100=22.2%











The answer to c) is 4/9 = 0.44. 0.44x100 = 44.4%











The answer to d) is 6/9=2/3=0.66. 0.66x100=66.6%













Which strategy did you use each time? I used probability trees for each question.

5. Raoul spins the pointer on each spinner. Find the probability of each event.

a) green and a 2
b) red an an even number
c) green and a prime number
Use a tree diagram or a table to verify your answers
















The total possible outcomes for this problem is 10 (5x2=10)

The answer for a) is 1/10=0.1. 0.1x100=10%

The answer for b) is 2/10=1/5=0.2. 0.2x100=20%

The answer for c) is 3/10=0.3. 0.3x100=30%























That is all we did in class today, and we have to study for test tomorrow.
I choose Vincent to be the next scribe.