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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. 12^2
361
144
1024
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

2. 1/20
5%
2.449
A^2 + 2ab + b^2
512

3. √ 2
1.41
16
5%
64

4. to divide powers with the same base...
13
= the cube root of 8 = 2
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
16

5. 1/8
12.50%
A^2 + 2ab + b^2
87.50%
27

6. 3^4
16.67%
81
196
256

7. 11^2
16.67%
128
27
121

8. 2^2
Multiply the exponents 7^2(^3) = 7^6
256
4
64

9. 2^6
64
1.73
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
256

10. 19^2
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
1024
361
128

11. 17^2
16.67%
289
Multiply the exponents 7^2(^3) = 7^6
12.50%

12. 5^3
3125
{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}
1024
125

13. a negative number raised to an odd power...
8.33%
16.67%
...yields a negative result (-1)^57 = -1
1024

14. 1/6
16.67%
1024
128
You cannot simplify this one

15. to multiple powers with the same base...
Add the exponents and keep the base 7^3 x 7^5 = 7^8
4
512
7776

16. Prime Numbers between 1 - 100 (total of 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}
1024
A^2 + 2ab + b^2
32

17. 5^4
...yields a negative result (-1)^57 = -1
You cannot simplify this one
625
87.50%

18. Simplifying a root
{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}
8
216
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

19. 16^2
256
81
3125
13

20. 1/4
1296
25
25%
361

21. a negative number raised to an even power...
196
...yields a positive result (-1)^2 = 1
87.50%
= the cube root of 8 = 2

22. √ 4
(a-b)(a^2+ab+b^2)
2.449
(a+b)(a^2-ab+b^2)
2

23. 1/6
40%
2.449
16.66%
{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}

24. √25+16 = √41
You cannot simplify this one
1.73
125
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3

25. a^3+b^3
256
2.23
(a+b)(a^2-ab+b^2)
216

26. √ 6
2.449
225
1296
...yields a positive result (-1)^2 = 1

27. 2^9
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
512
256
225

28. 15^2
8.33%
1.73
225
625

29. 6^4
40%
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}
1296

30. 2^10
1024
169
1.73
50%

31. 6^5
7776
1024
(a+b)(a^2-ab+b^2)
= the cube root of 8 = 2

32. to multiple powers (or raise a power to a power)
Multiply the exponents 7^2(^3) = 7^6
25
25%
3125

33. Multiples of 8
16.67%
(a+b)(a^2-ab+b^2)
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
144

34. 2^3
8
You cannot simplify this one
3125
243

35. 3^5
1.73
243
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
144

36. √ 625
7776
1024
25
...yields a positive result (-1)^2 = 1

37. 2^5
32
= the square root of 9 = 3
50%
324

38. Examples of roots simplification
121
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
75%
256

39. 2^7
128
25%
...yields a positive result (-1)^2 = 1
625

40. √ 5
121
2.23
20%
16.66%

41. 3/4
75%
8
3125
...yields a positive result (-1)^2 = 1

42. 1/5
64
169
20%
324

43. A^2-B^2
64
16.66%
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
(A+B)(A-B)

44. √ 3
128
25%
...yields a positive result (-1)^2 = 1
1.73

45. 2^4
121
196
16
= the cube root of 8 = 2

46. Multiples of 12
289
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
32
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120

47. Express 9^1/2 as a radical
361
243
(A+B)(A-B)
= the square root of 9 = 3

48. 5/6
75%
2.23
25
83.33%

49. 4^4
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
Add the exponents and keep the base 7^3 x 7^5 = 7^8
256

50. 5^5
144
(a+b)(a^2-ab+b^2)
16.66%
3125