Probability - Shortcuts with examples - Quantitative Aptitude
Its calculating the chance of a given event's occurrence.
Probability = No Of Favorable Events / No Of Total Possible
Events
Coin:
Probability of Event: Outcome of getting H or T is an event
Probability of Sample Space: Set of all possible outcomes è S = {H, T}
Probability of Equally likely Events: Events that have same
theoretical probability of occurrence è
H or T is equally likely to occur when it tossed
Probability of Mutually Exclusive Events: In simple words, A
can occur or B can occur but not both è
Occurrence of H and T are mutually exclusive events
Probability of Compound Events: Probability of joining the occurrence
of two or more events happening è there is a probability
of getting T in the first event and H in the second event
Die:
Probability of Random Experiment: When you rolled a die,
outcome will be a random number from 1-6
Probability of Event: Outcome of getting 1/2/3/4/5/6 is an
event
Probability of Sample Space: S = {1,2,3,4,5,6}
Probability of Equally likely Events: all 6 faces 1,2,3,4,5,6
is equally likely to occur when it rolled
Probability of Mutually Exclusive Events: all 6 faces 1,2,3,4,5,6
can’t come at a time
Cards:
Pack of cards will have 52…those are as below:
Spades (13 – Black coloured) è
9 numbered cards from 2-10, Ace, King, Queen and Jack
Clubs (13 – Black coloured) è
9 numbered cards from 2-10, Ace, King, Queen and Jack
Hearts (13 – Red coloured) è
9 numbered cards from 2-10, Ace, King, Queen and Jack
Diamonds (13 – Red coloured) è
9 numbered cards from 2-10, Ace, King, Queen and Jack
Ex: A man draws two cards with replacement from a pack of
card. What is the probability of a diamond in the first draw and king in the
second draw?
Sol: Probability of Diamond * Probability of a King
ð
We will have 13 diamonds and 4 kings in card
pack. Total number of cards will be 52
ð
:: 13/52 * 4/52 è
1/52 is the required probability
Ex: A coin is tossed thrice. What is the probability of
getting head all the time?
Sol: coin will have two faces
ð
1/2 * 1/2 * 1/2 = 1/8 is the required
probability
You could also look at below shortcut technics:
How To Solve Simplification Arithmetic Aptitude Questions
How To Solve Average Arithmetic Aptitude Questions
You could also look at below shortcut technics:
How To Solve Simplification Arithmetic Aptitude Questions
How To Solve Average Arithmetic Aptitude Questions