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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. 2^4
= the square root of 9 = 3
16
1.73
87.50%

2. 17^2
= the square root of 9 = 3
5%
8
289

3. a^3-b^3
(a-b)(a^2+ab+b^2)
20%
50%
A^2 + 2ab + b^2

4. 13^2
169
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
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
5%

5. Multiples of 12
...yields a smaller result (1/2)^2 = 1/4
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
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
1024

6. √ 4
64
27
1024
2

7. 2^2
4
625
2
25%

8. 1/5
20%
4
Add the exponents and keep the base 7^3 x 7^5 = 7^8
1.73

9. a^3+b^3
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
87.50%
Multiply the exponents 7^2(^3) = 7^6
(a+b)(a^2-ab+b^2)

10. 3^4
64
81
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

11. √ 6
20%
2.449
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
(a+b)(a^2-ab+b^2)

12. √ 5
2.449
1024
2.23
64

13. a negative number raised to an even power...
324
256
25%
...yields a positive result (-1)^2 = 1

14. 1/6
2
12.50%
83.33%
16.66%

15. 16^2
225
(a-b)(a^2+ab+b^2)
(a+b)(a^2-ab+b^2)
256

16. √ 625
2
50%
25
...yields a smaller result (1/2)^2 = 1/4

17. 2^8
256
3125
83.33%
169

18. 1/12
(a+b)(a^2-ab+b^2)
20%
32
8.33%

19. what happens when an exponent is negative?
You cannot simplify this one
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
Add the exponents and keep the base 7^3 x 7^5 = 7^8
64

20. 1/2
Multiply the exponents 7^2(^3) = 7^6
512
83.33%
50%

21. 7/8
27
...yields a smaller result (1/2)^2 = 1/4
40%
87.50%

22. to multiple powers (or raise a power to a power)
196
225
Multiply the exponents 7^2(^3) = 7^6
4

23. 4^5
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
81
169
1024

24. 1/8
3125
12.50%
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
144

25. 19^2
2.449
361
75%
...yields a negative result (-1)^57 = -1

26. (a-b)^2 =
125
5%
1.41
A^2 - 2ab + b^2

27. to multiple powers with the same base...
Add the exponents and keep the base 7^3 x 7^5 = 7^8
1024
16
...yields a smaller result (1/2)^2 = 1/4

28. Prime Numbers between 1 - 100 (total of 25)
...yields a smaller result (1/2)^2 = 1/4
1296
13
{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}

29. 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
1.41
64
50%

30. Examples of roots simplification
256
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
225
12.50%

31. 5/6
256
81
83.33%
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

32. 2^7
27
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
128
1296

33. 6^5
256
7776
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
A^2 - 2ab + b^2

34. 2^3
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
3125
256
8

35. to divide powers with the same base...
12.50%
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
50%

36. √25+16 = √41
1.41
You cannot simplify this one
2.449
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

37. Multiples of 15
361
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
121

38. Simplifying a root
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
289
125
A^2 + 2ab + b^2

39. √ 169
13
Multiply the exponents 7^2(^3) = 7^6
2.449
12.50%

40. 5^3
87.50%
125
20%
144

41. raising a fraction between zero and 1 to a power...
125
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
...yields a smaller result (1/2)^2 = 1/4
1024

42. 6^4
1296
1024
87.50%
3125

43. 15^2
121
225
50%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120

44. √ 2
20%
324
2.449
1.41

45. 3^3
{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}
7776
64
27

46. 1/6
(a-b)(a^2+ab+b^2)
625
16.67%
83.33%

47. 5^4
324
625
225
...yields a negative result (-1)^57 = -1

48. 1/20
40%
27
5%
121

49. 2/5
5%
25
1024
40%

50. Multiples of 8
7776
169
216
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120