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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. 2^10
16.67%
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
1024
A^2 + 2ab + b^2

2. Multiples of 12
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^2 - 2ab + b^2
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
125

3. 4^5
87.50%
5%
1024
196

4. 14^2
196
121
{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}
= the cube root of 8 = 2

5. A^2-B^2
512
196
87.50%
(A+B)(A-B)

6. 2^5
324
32
...yields a negative result (-1)^57 = -1
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

7. 3/4
= the cube root of 8 = 2
64
75%
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

8. 2^8
32
3125
8.33%
256

9. 2^4
16
1024
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
4

10. 2^6
216
1024
...yields a positive result (-1)^2 = 1
64

11. 5^3
81
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
16
125

12. √ 5
2.23
256
16.67%
512

13. 5/6
4
83.33%
256
125

14. 18^2
75%
324
50%
361

15. 3^3
12.50%
16.66%
27
A^2 + 2ab + b^2

16. what happens when an exponent is negative?
50%
7776
196
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

17. 11^2
(a-b)(a^2+ab+b^2)
32
121
144

18. 12^2
225
Multiply the exponents 7^2(^3) = 7^6
144
1.41

19. (a-b)^2 =
25%
(a+b)(a^2-ab+b^2)
40%
A^2 - 2ab + b^2

20. Examples of roots simplification
512
16
5%
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3

21. 2^9
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
256
2.449
512

22. √25+16 = √41
{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}
289
...yields a smaller result (1/2)^2 = 1/4
You cannot simplify this one

23. √ 2
1.41
256
You cannot simplify this one
128

24. √ 6
243
2.449
289
5%

25. 4^3
64
Multiply the exponents 7^2(^3) = 7^6
1024
...yields a positive result (-1)^2 = 1

26. 1/12
87.50%
3125
27
8.33%

27. 6^5
128
13
7776
= the cube root of 8 = 2

28. 4^4
256
121
1296
625

29. 1/20
5%
216
3125
625

30. 1/6
16.67%
81
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
2.23

31. Prime Numbers between 1 - 100 (total of 25)
169
{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}
256
243

32. √ 3
2.449
1.73
8
You cannot simplify this one

33. √ 169
= the cube root of 8 = 2
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
13
87.50%

34. to multiple powers with the same base...
Add the exponents and keep the base 7^3 x 7^5 = 7^8
A^2 + 2ab + b^2
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
512

35. 2^7
128
Add the exponents and keep the base 7^3 x 7^5 = 7^8
64
4

36. √ 4
256
16.67%
2
(a-b)(a^2+ab+b^2)

37. raising a fraction between zero and 1 to a power...
...yields a smaller result (1/2)^2 = 1/4
16.67%
361
16.66%

38. Multiples of 15
128
20%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
50%

39. Express 8^1/3 as a radical
= the square root of 9 = 3
87.50%
196
= the cube root of 8 = 2

40. 13^2
256
169
= the cube root of 8 = 2
324

41. a negative number raised to an even power...
8
83.33%
...yields a positive result (-1)^2 = 1
256

42. 2^3
You cannot simplify this one
5%
256
8

43. 16^2
40%
87.50%
2
256

44. 2^2
Add the exponents and keep the base 7^3 x 7^5 = 7^8
Multiply the exponents 7^2(^3) = 7^6
You cannot simplify this one
4

45. √ 625
13
64
25
5%

46. 7/8
87.50%
25%
8
A^2 - 2ab + b^2

47. to divide powers with the same base...
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
8
512
1024

48. Express 9^1/2 as a radical
27
= the square root of 9 = 3
625
7776

49. 5^4
12.50%
625
361
1024

50. to multiple powers (or raise a power to a power)
Multiply the exponents 7^2(^3) = 7^6
...yields a negative result (-1)^57 = -1
(a-b)(a^2+ab+b^2)
You cannot simplify this one