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GMAT Quick Math And Formulas

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. a negative number raised to an even power...
512
225
...yields a positive result (-1)^2 = 1
32

2. 5^4
2.449
625
25
Multiply the exponents 7^2(^3) = 7^6

3. Simplifying a root
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
256
16.66%
GMAT very often tries to trick you by giving a root linked by addition where it is tempting to simplify the terms - for example: √(25 + 16). It is tempting to think that this will result into 5 + 4 - but you can only simplify roots when the terms ins

4. what happens when an exponent is negative?
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
A^2 - 2ab + b^2
50%

5. 7/8
324
87.50%
83.33%
27

6. Multiples of 8
5%
512
25
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120

7. (a+b)^2 =
...yields a negative result (-1)^57 = -1
169
87.50%
A^2 + 2ab + b^2

8. √ 6
7776
225
144
2.449

9. 6^5
7776
625
27
64

10. Multiples of 12
A^2 + 2ab + b^2
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
3125
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

11. 3^3
...yields a smaller result (1/2)^2 = 1/4
A^2 - 2ab + b^2
81
27

12. Prime Numbers between 1 - 100 (total of 25)
169
25
{2 -3 -5 -7 -11 -13 -17 -19 -23 -29 -31 -37 -41 -43 -47 -53 -59 -61 -67 -71 -73 -79 -83 -89 -97}
20%

13. Express 9^1/2 as a radical
83.33%
You cannot simplify this one
= the square root of 9 = 3
50%

14. 14^2
196
3125
256
144

15. 1/8
27
5%
12.50%
169

16. A^2-B^2
243
(A+B)(A-B)
...yields a negative result (-1)^57 = -1
1296

17. to divide powers with the same base...
(A+B)(A-B)
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
324
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120

18. 17^2
...yields a positive result (-1)^2 = 1
256
289
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

19. 5^5
144
3125
16.67%
625

20. √25+16 = √41
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
2
You cannot simplify this one
2.23

21. 1/6
16.66%
361
(A+B)(A-B)
25%

22. a negative number raised to an odd power...
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
GMAT very often tries to trick you by giving a root linked by addition where it is tempting to simplify the terms - for example: √(25 + 16). It is tempting to think that this will result into 5 + 4 - but you can only simplify roots when the terms ins
...yields a negative result (-1)^57 = -1
256

23. 3^5
(a+b)(a^2-ab+b^2)
243
= the square root of 9 = 3
225

24. 4^4
(a+b)(a^2-ab+b^2)
128
256
2.449

25. √ 169
13
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
243
...yields a smaller result (1/2)^2 = 1/4

26. 13^2
169
512
...yields a negative result (-1)^57 = -1
2

27. 2^4
8.33%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
324
16

28. Multiples of 15
...yields a smaller result (1/2)^2 = 1/4
121
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
81

29. raising a fraction between zero and 1 to a power...
...yields a smaller result (1/2)^2 = 1/4
GMAT very often tries to trick you by giving a root linked by addition where it is tempting to simplify the terms - for example: √(25 + 16). It is tempting to think that this will result into 5 + 4 - but you can only simplify roots when the terms ins
20%
7776

30. 1/20
5%
1024
256
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3

31. 1/2
50%
GMAT very often tries to trick you by giving a root linked by addition where it is tempting to simplify the terms - for example: √(25 + 16). It is tempting to think that this will result into 5 + 4 - but you can only simplify roots when the terms ins
(A+B)(A-B)
225

32. 2^7
128
(a+b)(a^2-ab+b^2)
256
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120

33. 1/4
64
25%
125
A^2 - 2ab + b^2

34. 18^2
1024
1.73
8
324

35. √ 625
16
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
2
25

36. (a-b)^2 =
2.23
A^2 - 2ab + b^2
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

37. 12^2
You cannot simplify this one
256
512
144

38. a^3+b^3
27
32
(a+b)(a^2-ab+b^2)
128

39. 2^6
4
81
64
...yields a negative result (-1)^57 = -1

40. 16^2
16.67%
A^2 + 2ab + b^2
512
256

41. 3^4
13
= the cube root of 8 = 2
81
64

42. Express 8^1/3 as a radical
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
83.33%
169
= the cube root of 8 = 2

43. 1/12
243
8.33%
A^2 + 2ab + b^2
50%

44. 3/4
75%
...yields a smaller result (1/2)^2 = 1/4
(a-b)(a^2+ab+b^2)
81

45. 1/6
A^2 + 2ab + b^2
16.67%
4
5%

46. 2^8
12.50%
GMAT very often tries to trick you by giving a root linked by addition where it is tempting to simplify the terms - for example: √(25 + 16). It is tempting to think that this will result into 5 + 4 - but you can only simplify roots when the terms ins
Multiply the exponents 7^2(^3) = 7^6
256

47. √ 2
1.41
1296
{2 -3 -5 -7 -11 -13 -17 -19 -23 -29 -31 -37 -41 -43 -47 -53 -59 -61 -67 -71 -73 -79 -83 -89 -97}
27

48. to multiple powers with the same base...
16
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
25
Add the exponents and keep the base 7^3 x 7^5 = 7^8

49. 2^5
20%
...yields a positive result (-1)^2 = 1
= the cube root of 8 = 2
32

50. 2^10
1024
196
1296
216