All GRE Subject Test: Math Resources
Example Questions
Example Question #92 : Probability & Statistics
How many three-digit numbers can I create from the set of numbers ?
Step 1: Identify if there are any restrictions to how the numbers can be made...
There are no restrictions, so we can have repeating numbers.
Step 2: Determine how many numbers can go in each slot..
First Slot: 7 choices
Second Slot: 7 Choices
Third Slot: 7 choices
Step 3: Multiply the choices for all three sets together:
We can create different three-digit numbers...
Example Question #41 : Combinational Analysis
How many non-repetitive three-digit numbers can I create from the set of numbers ?
Step 1: See if there are any restrictions..
We see we want only non-repetitive numbers...
Step 2: Find how many numbers can be put in each spot:
First Spot:
Second Spot:
Third Spot:
Step 3: Multiply the number of choices of each spot
I can create non-repetitive three-digit numbers...
Example Question #42 : Combinational Analysis
How many ways can I arrange the letters in the word ?
Step 1: Count how many letters are in the word MISSISSIPPI...
There are 11 numbers.
Step 2: Find which letters repeat, and how many times it repeats:
times
times
times
Step 3: Use formula for arranging letters:
Step 4: Expand:
Step 5: Simplify Step 4:
I can rearrange the letters in MISSISSIPPI times...
Example Question #51 : Combinational Analysis
How many ways can I arrange the letters in the word CORRECT?
Step 1: Count how many letters are in the word CORRECT...
There are letters.
Step 2: Find any letters that repeat and how many times they repeat:
C (two times), R (two times)
Step 3: Find how many ways can I arrange the letters:
Example Question #52 : Combinational Analysis
people are at a farewell party. At the end of the night, each person shakes hands. How many handshakes are made?
NOTE: No two people can shake hands more than once.
Step 1: Determine how many people are there..
There are people.
Step 2: Determine how many people shake hands in a handshake...
people make one handshake.
Step 3: Determine how many handshakes can be made...
We have a restriction here, so we need to use permutation..
So, there will be handshakes.
handshakes
Example Question #101 : Probability & Statistics
In how many ways can I rearrange the letters in the word "ANACONDA"?
Step 1: Count how many letters are in the word ANACONDA...
There are 8 letters.
Step 2: Count how many repeats of any letters (if any)..
There are A's and N's.
Step 3: Find how many ways I can rearrange...
Example Question #101 : Probability & Statistics
How many ways can I arrange the letters in the word ?
Step 1: Count how many numbers are in the word...
There are letters.
Step 2: Count the number of repeated letters...
There are T's
There are O's
There are R's
Step 3: To find how many ways I can arrange the letters, take the factorial of the total number of letters and divide it by the factorial of how many times a certain letter repeats...
So,