GRE Math Flashcards
What are the common Pythagorean Triplets?
3,4,5
5,12,13
7,24,25
8,15,17
What is Pythagorean’s theorem?
a2 + b2 = c2
What is the formula for finding the area of a triangle?
1/2(base x height)
How do you calculate the circumference of a circle?
2pir
How do you calculate the area of a circle?
pi*r^2
What can you do to the numerator and denominator to make a fraction smaller?
Increase Denominator, Decrease Numerator
What is 1/100?
.01
What is 1/1000?
.001
What is 1/6?
0.16667 (repeating)
What is 5/6?
0.83334 (repeating)
What is 1/7?
0.143
What is 1/8?
0.125
What is 3/8?
0.375
What is 5/8?
0.625
What is 7/8?
0.875
What is 1/9?
.11112 (repeating)
If a number is bigger than 1, its reciprocal will fall where on the number line?
Between 0 and 1.
If a number is between 0 and 1, where will its reciprocal fall on the number line?
It is greater than 1.
How do you divide by a fraction?
Multiply by the reciprocal.
In a word problem “is” typically means?
Equals
In a word problem “of” typically means
“multiply”
What are all the prime #’s less than 20?
2, 3, 5, 7, 11, 13, 17, 19
What are the prime #’s between 20 and 60?
23, 29, 31, 37, 41, 43, 47, 53, 59
How do you check whether a number less than 100 is prime?
Check to see if it is divisible by 2, 3, 5, and 7.
What is the area of an equilateral triangle?
Root 3 / 4 * side ^ 2
When you add or subtract two even or two odd numbers, is the answer even or odd?
Even.
When you add or subtract an even and an odd number, is the result even or odd?
Odd
Zero is even.
When you multiply two even numbers, is the result even or odd?
Even
When you multiply two odd numbers, is the result even or odd?
Odd
When you multiply an even and an odd number, is the result even or odd?
Even
How do you use FOIL to multipy a binomial?
Take the First, Outer, Inner, and Last pairings, and add them together.
What is considered 1 standard deviation away from the mean?
34%
What is considered 2 standard deviations away from the mean?
13.5%
