Collection of mathematical
tasks in probability
Nella Fedorowyczová, 3.A
What is probability?
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part of high school Maths
there are more possible events
expresses how probable a particular event is
quotient = favourable events/all events
mostly a decimal number between 0 and 1
sometimes percents (between 0 and 100 %)
usable in real-life situations
Where do we use this?
A son? A daughter?
Who will be the winner?
Will I pass the exam?
Exercise 1
• St Mark's Square in Venice is 50 days
per year under water. What is the
probability that we will arrive in the
city in a day when the place will be
flooded? Don’t think about a leap
year.
How to solve it?
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favourable events ... 50
all events ... 365
probability ... ?
probability =
= favourable events/all events = = 50/365
= 10/73 (in round numbers 0,137 or 13,7
%)
Exercise 2
• Filip's grandmother has knitted up one
blue, one green and one brown sweater.
She has also knitted up a pair of gloves
and a cap in each of these colours. She is
preparing a gift parcel for Filip but she is
a bit muddle-headed person... What is
the probability that Filip will get all the
garments in the same colour?
How to solve it?
• favourable events... 3 (everything blue, brown
or green)
• all events... 27 (3 * 3 * 3)
• probability ... ?
• probability =
= favourable events/all events =
= 3/27 = 1/9 (in round numbers 0,111
or 11,1 %)
Extra exercise
• What is the probability that we will win the
first price in „Šťastných deset“? We choose 10
numbers out of 80.
How to solve it?
• predicted numbers ... 10
• drawn numbers ... 20
• all numbers ... 80
Thank you for your attention!
• http://www.cesky-hokej.cz/wp-content/gallery/hokej/hokej-1.jpg
• http://upload.wikimedia.org/math/a/7/9/a7909c72e1574fc5efc99062b9a
6fdbb.png
• http://www.fiftyfifty.cz/fotografie/2009-11-c2234106/Kluk-nebo-holka.jpg
• http://i.idnes.cz/11/033/cl6/SPI19fc64_sportka_micky.jpg
• http://media.novinky.cz/185/161853-top_foto1-j5741.jpg?1256146201
• http://www.e-vysledky.cz/images/688/stastnych_deset_sazenka.png