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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. 1/2
20%
(A+B)(A-B)
8.33%
50%

2. 19^2
50%
128
361
{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}

3. 2^9
20%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
512
196

4. what happens when an exponent is negative?
25%
13
216
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

5. 3/4
75%
32
Multiply the exponents 7^2(^3) = 7^6
(a-b)(a^2+ab+b^2)

6. 16^2
256
512
324
289

7. 6^4
1296
= the cube root of 8 = 2
...yields a positive result (-1)^2 = 1
32

8. √ 5
2.23
7776
16.67%
1.73

9. √ 2
5%
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
(A+B)(A-B)
1.41

10. 11^2
361
40%
121
8

11. Prime Numbers between 1 - 100 (total of 25)
2.449
512
{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}
A^2 - 2ab + b^2

12. 2^2
81
4
12.50%
64

13. 4^5
...yields a negative result (-1)^57 = -1
64
1024
75%

14. 1/20
5%
20%
256
8

15. 4^3
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
1024
1.41
64

16. 6^5
7776
3125
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
16.66%

17. 1/12
Multiply the exponents 7^2(^3) = 7^6
625
A^2 + 2ab + b^2
8.33%

18. 1/6
13
144
16.67%
50%

19. 5^4
256
128
625
(a+b)(a^2-ab+b^2)

20. 13^2
= the square root of 9 = 3
169
196
16.67%

21. 12^2
324
1024
144
Add the exponents and keep the base 7^3 x 7^5 = 7^8

22. 5/6
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
{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}
83.33%
121

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

24. 2^5
16.66%
64
32
25%

25. 2^6
289
2
64
1024

26. 1/8
...yields a positive result (-1)^2 = 1
{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}
12.50%
Multiply the exponents 7^2(^3) = 7^6

27. 2^3
8
...yields a negative result (-1)^57 = -1
A^2 + 2ab + b^2
(a-b)(a^2+ab+b^2)

28. Simplifying a root
= the cube root of 8 = 2
25%
1024
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

29. 6^3
75%
(a-b)(a^2+ab+b^2)
216
256

30. 2^10
2
1024
...yields a negative result (-1)^57 = -1
216

31. (a-b)^2 =
A^2 - 2ab + b^2
5%
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
Multiply the exponents 7^2(^3) = 7^6

32. Express 8^1/3 as a radical
289
324
256
= the cube root of 8 = 2

33. √ 4
2
40%
128
1024

34. 2^4
16
8.33%
{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}
25

35. raising a fraction between zero and 1 to a power...
25%
...yields a smaller result (1/2)^2 = 1/4
2.23
5%

36. 14^2
196
169
625
Add the exponents and keep the base 7^3 x 7^5 = 7^8

37. √ 6
625
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
2.449
20%

38. 7/8
87.50%
Add the exponents and keep the base 7^3 x 7^5 = 7^8
...yields a negative result (-1)^57 = -1
8

39. Examples of roots simplification
...yields a positive result (-1)^2 = 1
32
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
A^2 + 2ab + b^2

40. A^2-B^2
(A+B)(A-B)
5%
121
625

41. 1/5
20%
243
289
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

42. 17^2
16.67%
256
2
289

43. to multiple powers (or raise a power to a power)
Multiply the exponents 7^2(^3) = 7^6
40%
361
256

44. 5^5
3125
144
81
256

45. √ 625
25
81
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
13

46. to multiple powers with the same base...
...yields a negative result (-1)^57 = -1
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
Add the exponents and keep the base 7^3 x 7^5 = 7^8
20%

47. a^3+b^3
You cannot simplify this one
(a+b)(a^2-ab+b^2)
64
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3

48. 3^5
1.73
243
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
225

49. Express 9^1/2 as a radical
Add the exponents and keep the base 7^3 x 7^5 = 7^8
= the square root of 9 = 3
...yields a negative result (-1)^57 = -1
1.41

50. a^3-b^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
(A+B)(A-B)
1.41
(a-b)(a^2+ab+b^2)