Probability — Class 10 Maharashtra SSC Mathematics revision notes
A 4-page visual revision sheet for Probability, written for Class 10 Maharashtra SSC Mathematics. Formulas, diagrams and the traps that cost marks, laid out to be read the night before rather than the term before. Free, and it opens inside CapCompass.
Page 1 as PDFA preview of page 1 — all 4 pages open full size in the app.
Probability in one look
counting the favourable cases against all the equally likely ones, and the traps in the counting
The vocabulary, fixed before anything else
a random experiment has more than one possible result and none of them can be predicted with certainty
the sample space S is the set of every possible outcome, and n(S) is how many there are
an event A is any subset of the sample space, and n(A) is the count of outcomes favourable to it
outcomes must be equally likely for the formula below to apply, which is why we speak of a fair coin and an unbiased die
an elementary event has exactly one outcome, and a certain event is the whole sample space
two events are mutually exclusive when they cannot both happen, such as a die showing 2 and showing 5 on one throw
The results this chapter needs
probability of an eventP(A) = n(A)/n(S)
the range every probability lies in0 ≤ P(A) ≤ 1
the complement, A not happeningP(A) = 1 - P(A)
all elementary probabilities add to oneΣ P = 1
an impossible event, then a certain oneP = 0,quad P = 1
The standard sample spaces, worth knowing cold
Experiment
n(S)
Worth remembering
one coin
2
H, T
two coins
4
HH, HT, TH, TT
three coins
8
2 × 2 × 2
one die
6
1 to 6
two dice
36
ordered pairs, 6 × 6
a pack of cards
52
4 suits of 13
The pack of cards, in the detail questions use
52 cards in four suits of 13 each: spades, clubs, hearts and diamonds
spades and clubs are black, hearts and diamonds are red, so 26 of each colour
each suit runs ace, 2 to 10, then jack, queen and king, so there are 4 of every rank
the face cards are jack, queen and king, giving 3 per suit and 12 in the pack
an ace is not a face card, which is a distinction questions deliberately test
so there are 12 face cards, 6 of them red, and 16 cards that are either an ace or a face card
Page 1 of 4. The full sheet, all 4 pages, opens free in the app.
These notes are not a standalone PDF. CapCompass plans Mathematics chapter by chapter against your real exam dates and free hours, and when the plan reaches Probability the sheet opens inside the study block itself — at the page covering the sub-topic that block is on, with the timer still running. Revision arrives at the moment the plan says revise, instead of having to be gone looking for.