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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. Multiples of 8
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
64
324
= the square root of 9 = 3

2. 19^2
75%
1296
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
361

3. (a+b)^2 =
Multiply the exponents 7^2(^3) = 7^6
(A+B)(A-B)
A^2 + 2ab + b^2
40%

4. a^3+b^3
(a+b)(a^2-ab+b^2)
256
64
(a-b)(a^2+ab+b^2)

5. √ 2
50%
1.41
20%
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

6. 2^5
1024
1296
32
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120

7. 12^2
...yields a smaller result (1/2)^2 = 1/4
...yields a positive result (-1)^2 = 1
256
144

8. 3^3
125
27
40%
= the square root of 9 = 3

9. Express 8^1/3 as a radical
13
4
83.33%
= the cube root of 8 = 2

10. 15^2
225
243
256
40%

11. 1/12
8.33%
(A+B)(A-B)
75%
625

12. Express 9^1/2 as a radical
40%
= the square root of 9 = 3
13
8

13. 4^5
1024
(A+B)(A-B)
196
...yields a negative result (-1)^57 = -1

14. 11^2
7776
2.23
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
121

15. 5^5
3125
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
1.73
20%

16. 17^2
81
289
125
2.449

17. 2^8
243
16.66%
16
256

18. 6^5
{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
289
Add the exponents and keep the base 7^3 x 7^5 = 7^8

19. 1/4
25%
25
83.33%
8

20. 2^9
512
32
2.449
1.41

21. 2^2
4
512
16.67%
16.66%

22. a negative number raised to an even power...
...yields a positive result (-1)^2 = 1
121
25
A^2 + 2ab + b^2

23. 2^4
216
8
256
16

24. 3/4
75%
512
256
216

25. 18^2
324
144
8.33%
128

26. 2^6
5%
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
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
64

27. (a-b)^2 =
1024
A^2 - 2ab + b^2
40%
7776

28. 5^3
125
40%
243
512

29. 1/6
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
16.67%
256
32

30. 3^4
16.66%
81
512
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120

31. 6^4
1296
16.66%
5%
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

32. √ 4
1.73
40%
A^2 - 2ab + b^2
2

33. to multiple powers with the same base...
243
Add the exponents and keep the base 7^3 x 7^5 = 7^8
40%
289

34. Multiples of 15
121
128
16
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120

35. 5^4
87.50%
75%
1.73
625

36. Multiples of 12
= the square root of 9 = 3
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
361
216

37. raising a fraction between zero and 1 to a power...
...yields a positive result (-1)^2 = 1
50%
25
...yields a smaller result (1/2)^2 = 1/4

38. √ 3
16
1.73
7776
625

39. √ 6
2.449
512
625
256

40. what happens when an exponent is negative?
You cannot simplify this one
625
8
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

41. 7/8
8
87.50%
(A+B)(A-B)
64

42. to divide powers with the same base...
16.67%
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
8.33%
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3

43. 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
144
8
8.33%

44. √ 5
A^2 + 2ab + b^2
= the square root of 9 = 3
2.23
225

45. 2^10
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
289
1024
243

46. 6^3
(a+b)(a^2-ab+b^2)
4
216
...yields a smaller result (1/2)^2 = 1/4

47. to multiple powers (or raise a power to a power)
Multiply the exponents 7^2(^3) = 7^6
{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}
121
13

48. 1/8
12.50%
225
361
8.33%

49. 4^3
121
64
(A+B)(A-B)
32

50. Prime Numbers between 1 - 100 (total of 25)
81
{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%
216