Test your basic knowledge |

GMAT Quantitative General

Subjects : gmat, math

Instructions:

Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can study here.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. Set Problems formula
(x-n(n)y-n)
gcd(m,n)*lcm(m,n) = mn
x - x - x(sq. rt 2)
1. Start by writing each number as a product of primes. 2. Write so that each new prime factor begins in the same place. 3. Lowest common multiple is found by multiplying all factors in either list.

2. Formula for Mixed Group problems (involving Both/Neither)
sum = (average)(number of terms)
1.4
A = P(1 + r) ^n
Group 1 + Group 2 + Neither - Both = Total

3. 1/8 = what %
Sum of digits is multiple of 3
The number of ways independent events can occur together can be determined by multiplying together the number of possible outcomes for each event.
12.5%
If the outcome of one event affects the outcome of the other event.

4. Compound interest rule
s Sq. rt (x^r)
Any multiplication involving an even number creates an even product.
Organize into a grid.
Find simple interest then look for the answer that is a little bigger

5. 2nd Rule of Probability: P(E) = 1 - P(not E)
22
The probability of an event occurring plus the probability of the event not occurring = 1
180(n-2)
Group 1 + Group 2 + Neither - Both = Total

6. Price purchased for by wholesaler
The probability of event A OR B occurring is the probability of event A occurring plus the probability of event B occurring minus the probability of both events occurring. P(A or B) = P(A) +P(B) - P(A and B)
s Sq. rt (x^r)
Purchase price
If the outcome of one event affects the outcome of the other event.

7. When you see an equation in factored form in a question?
Sum of digits is multiple of 9
(x-n(n)y-n)
Immediately UNFACTOR or vice versa
3-4-5 - 5-12-13 - 9-12-15

8. gcd(m,n)*lcm(m,n)
180(n-2)
(total distance) / (total time)
Even integer. Neither positive nor negative. Multiple of every number. Not a factor of any number.
gcd(m,n)*lcm(m,n) = mn

9. Gross Profit formula
Check each prime number up to the approximate square root of the number. If you haven't found a number less than or equal to the square root of the number - then the number is prime.
Gross Profit = Selling Price - Cost
(amount of change) / (original amount)
Divide 4999 by 15 => 333 integers

10. How to check whether a number is a multiple of 6
Sum of digits is multiple of 9
12.5%
s Sq. rt (x^r)
Number is a multiple of 3 and 2

11. Simple probability
(# of favorable outcomes) / (# of possible outcomes)
180(n-2)
The amount after deductions
Balancing

12. The number of outcomes that result in A divided by the total number of possible outcomes.
1. Start by writing each number as product of primes. 2. Write so that each new prime factor begins in the same place. 3. Greatest Common Factor is found by multiplying all factors appearing in BOTH lists
D or E
1.7
The probability of event occurring is...

13. How many liters of a solution that is 15% salt must be added to 5 liters of a solution that is 8% salt so that the resulting mixture is 10% salt?
Exterior angle d is equal to the sum of the two remote interior angles a and b
(x-n(n)y-n)
Number is a multiple of 3 and 2
0.15n + 0.08(5) = 0.1(n+5)

14. To determine the number of integers less than 5000 that are evenly divisible by 15...?
s Sq. rt (x^r)
Balancing
12^3
Divide 4999 by 15 => 333 integers

15. How to check whether number is multiple of 9
If the outcome of one event affects the outcome of the other event.
Sum of digits is multiple of 9
Sum of digits is multiple of 3
180(n-2)

16. Average Rate: Average speed
(total distance) / (total time)
To find the number of distinct permutations of a set of items with indistinguishable ('repeat') items - divide the factorial of the items in the set by the product of the factorials of the number of indistinguishable elements.
Divide 4999 by 15 => 333 integers
Immediately try factoring/simplifying when possible

17. In general - medium questions require how many steps to solve?
Last two digits are multiple of 4 or the number can be divided by 2 twice.
______ |m-n|
(n-1)!
2 steps

18. x^r/s = ?
1.4
(x-n(n)y-n)
s Sq. rt (x^r)
4/3 TT r ^3

19. The number of ways independent events can occur together.
Sum of digits is multiple of 3 - last two digits multiple of 4.
Immediately UNFACTOR or vice versa
p/100 = is/of
The number of ways independent events can occur together can be determined by multiplying together the number of possible outcomes for each event.

20. Since Mieko's average speed was 3/4 of Chan's - her time was 4/3 as long.
D or E
For a fixed distance - the average speed is inversely related to the amount of time required to make the trip.
P(E) + P(F) - P(E and F)
Check each prime number up to the approximate square root of the number. If you haven't found a number less than or equal to the square root of the number - then the number is prime.

21. 3^3 x 4^3 = ?
12.5%
Any multiplication involving an even number creates an even product.
12^3
14 liters

22. 5/6 = what %
always try to factor
3-4-5 - 5-12-13 - 9-12-15
______ |m-n|
83.3%

23. Price sold for by retailer (after markup)
Find simple interest then look for the answer that is a little bigger
market value
Minor arc = 2(inscribed angle)
(total A) / (total B)

24. Sq. rt(3)
1.7
the probability of event A AND event B occurring is the probability of event A times the probability of event B - given that A has already occurred.
at least 3 steps
y2 - y1 / x2 - x1

25. Circular permutation: The number of ways to arrange n distinct objects along a fixed circle is?
Find all prime factors
(sum of bases)(height) / 2
(n-1)!
3 - 6 - 9 - 12

26. Multiples of 3
Purchase price
x - x - x(sq. rt 2)
2 steps
3 - 6 - 9 - 12

27. 30-60-90 triangle basic lengths of sides
(sum of bases)(height) / 2
x(sq. rt 3) - x - 2x
Group 1 + Group 2 + Neither - Both = Total
The amount after deductions

28. Some GMAT word problems involve groups with distinct 'either/or' categories (male/female - blue collar/white collar - etc.) The key is to do what with the information? 1. Find total number of possible outcomes. 2. Find the number of desired outcomes.
y2 - y1 / x2 - x1
P(E)P(F)
Organize into a grid.
For a fixed distance - the average speed is inversely related to the amount of time required to make the trip.

29. (1/4)^2
347
Minor arc = 2(inscribed angle)
1/16
16.6%

30. Odd Factors
Even integer. Neither positive nor negative. Multiple of every number. Not a factor of any number.
Odd numbers only have ___________
1
1.4

31. Dependent events: When are two events said to be dependent events?
______ |m-n|
If the outcome of one event affects the outcome of the other event.
The probability of an event occurring plus the probability of the event not occurring = 1
The amount after deductions

32. How to check whether a number is a multiple of 4.
0.15n + 0.08(5) = 0.1(n+5)
Last two digits are multiple of 4 or the number can be divided by 2 twice.
If the outcome of one event affects the outcome of the other event.
multiply or divide the numbers outside the radical signs - then the numbers inside the radical signs

33. Work problem rule
y2 - y1 / x2 - x1
12.5%
(# of favorable outcomes) / (# of possible outcomes)
Consider work done in one hour. Inverse of the time it takes everyone working together = Sum of the inverse of the times it would take each person working individually.

34. Inscribed Angle - Minor Arc
Minor arc = 2(inscribed angle)
Purchase price
Figure out the probability for each individual event. Multiply the individual probabilities together.
4/3 TT r ^3

35. Properties of 0
Even integer. Neither positive nor negative. Multiple of every number. Not a factor of any number.
P(event NOT occurring) = 1 - P(event occurring)
3 - 6 - 9 - 12
Figure out the probability for each individual event. Multiply the individual probabilities together.

36. Compound interest formula
Principal (1 + interest/number times compounded)^(t)(n)
22
A = P(1 + r) ^n
always try to factor

37. What to do with equations that have fractions
Immediately try factoring/simplifying when possible
Even integer. Neither positive nor negative. Multiple of every number. Not a factor of any number.
Check each prime number up to the approximate square root of the number. If you haven't found a number less than or equal to the square root of the number - then the number is prime.
12^3

38. How to check whether a number is a multiple of 3.
Any multiplication involving an even number creates an even product.
If a point is chosen at random within a space with an area - volume - or length of Y and a space with a respective area - volume - or length of X lies within Y - the probability of choosing a random point within Y is the area - volume - or length of
Sum of digits is multiple of 3
Gross Profit = Selling Price - Cost

39. In general - difficult questions require how many steps to solve?
1
at least 3 steps
To find the number of distinct permutations of a set of items with indistinguishable ('repeat') items - divide the factorial of the items in the set by the product of the factorials of the number of indistinguishable elements.
-b +- sq. rt(b^2 - 4ac) / 2a

40. 2n - 2n+2 - 2n+4
Total = mean x (number of terms) Number deleted = (original total) - (new total) Number added = (new total) - (original total)
(x-n(n)y-n)
Even
1

41. Formula for area of a Trapezoid
(sum of bases)(height) / 2
Find all prime factors
Even
Sum of digits is multiple of 3

42. Average Rate: Average A per B
(total A) / (total B)
To find the number of distinct permutations of a set of items with indistinguishable ('repeat') items - divide the factorial of the items in the set by the product of the factorials of the number of indistinguishable elements.
sum = (average)(number of terms)
Immediately try factoring/simplifying when possible

43. Combined Events: E and F
Odd numbers only have ___________
0.15n + 0.08(5) = 0.1(n+5)
Balancing
P(E)P(F)

44. How to check for a prime number.

45. Net
(x-n(n)y-n)
The amount after deductions
Odd
Divide 4999 by 15 => 333 integers

46. Volume of a sphere
Any multiplication involving an even number creates an even product.
n! / (n - r)!
4/3 TT r ^3
y2 - y1 / x2 - x1

47. Quadratic formula
-b +- sq. rt(b^2 - 4ac) / 2a
16.6%
always try to factor
1. Start by writing each number as a product of primes. 2. Write so that each new prime factor begins in the same place. 3. Lowest common multiple is found by multiplying all factors in either list.

48. Probability and Geometry.
22
at least 3 steps
(total distance) / (total time)
If a point is chosen at random within a space with an area - volume - or length of Y and a space with a respective area - volume - or length of X lies within Y - the probability of choosing a random point within Y is the area - volume - or length of

49. 4th rule of Probability
The probability of event A OR B occurring is the probability of event A occurring plus the probability of event B occurring minus the probability of both events occurring. P(A or B) = P(A) +P(B) - P(A and B)
347
gcd(m,n)*lcm(m,n) = mn
Total = mean x (number of terms) Number deleted = (original total) - (new total) Number added = (new total) - (original total)

50. Triangle abc with d on the outside with a line. What does d = ?
s Sq. rt (x^r)
Figure out the probability for each individual event. Multiply the individual probabilities together.
Odd
Exterior angle d is equal to the sum of the two remote interior angles a and b