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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. 2^7
2.23
4
128
75%

2. to divide powers with the same base...
1024
16.66%
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
(a-b)(a^2+ab+b^2)

3. 2^8
256
= the square root of 9 = 3
1024
20%

4. 1/2
50%
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
361
1296

5. 6^4
A^2 + 2ab + b^2
1296
256
243

6. 2^4
16
243
= the cube root of 8 = 2
You cannot simplify this one

7. 2/5
40%
3125
128
A^2 + 2ab + b^2

8. 13^2
169
(a+b)(a^2-ab+b^2)
512
...yields a smaller result (1/2)^2 = 1/4

9. 2^2
12.50%
4
64
289

10. (a+b)^2 =
A^2 + 2ab + b^2
125
4
= the cube root of 8 = 2

11. 17^2
289
1.41
83.33%
324

12. Simplifying a root
12.50%
= the cube root of 8 = 2
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
Multiply the exponents 7^2(^3) = 7^6

13. Multiples of 15
20%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
81
...yields a negative result (-1)^57 = -1

14. 19^2
(A+B)(A-B)
216
512
361

15. 2^9
16.67%
512
(A+B)(A-B)
8

16. 7/8
144
13
87.50%
1024

17. 14^2
196
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
75%
4

18. 5^3
Multiply the exponents 7^2(^3) = 7^6
225
125
40%

19. 3^5
243
Multiply the exponents 7^2(^3) = 7^6
64
A^2 - 2ab + b^2

20. 16^2
64
...yields a positive result (-1)^2 = 1
256
Multiply the exponents 7^2(^3) = 7^6

21. 1/6
Multiply the exponents 7^2(^3) = 7^6
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
16.67%
A^2 + 2ab + b^2

22. 6^3
216
25%
512
256

23. Prime Numbers between 1 - 100 (total of 25)
2.449
{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}
16.66%
1.41

24. to multiple powers (or raise a power to a power)
8
512
Multiply the exponents 7^2(^3) = 7^6
(A+B)(A-B)

25. A^2-B^2
256
...yields a negative result (-1)^57 = -1
(A+B)(A-B)
{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}

26. 5/6
8
16
83.33%
81

27. 1/6
13
16.66%
361
27

28. 6^5
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
Multiply the exponents 7^2(^3) = 7^6
324
7776

29. a negative number raised to an odd power...
13
...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
40%

30. 12^2
324
144
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
32

31. 3/4
Add the exponents and keep the base 7^3 x 7^5 = 7^8
75%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
169

32. √ 4
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
2
3125
196

33. 5^4
625
{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}
...yields a smaller result (1/2)^2 = 1/4
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120

34. 1/20
5%
225
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
50%

35. √ 6
You cannot simplify this one
1024
2.449
{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}

36. √ 5
1.73
87.50%
32
2.23

37. 5^5
128
1.41
50%
3125

38. 1/5
20%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
(A+B)(A-B)
128

39. √ 3
1.73
= the cube root of 8 = 2
361
2.449

40. 4^3
16.66%
64
83.33%
625

41. 4^5
1024
361
...yields a positive result (-1)^2 = 1
169

42. what happens when an exponent is negative?
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
{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%
1.73

43. a^3-b^3
(a-b)(a^2+ab+b^2)
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
125
64

44. √25+16 = √41
40%
1024
87.50%
You cannot simplify this one

45. √ 169
...yields a positive result (-1)^2 = 1
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
13
625

46. Examples of roots simplification
A^2 - 2ab + b^2
81
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
256

47. √ 625
25
64
169
256

48. 3^3
27
16.66%
1296
83.33%

49. 2^10
= the cube root of 8 = 2
8.33%
289
1024

50. 3^4
16.67%
...yields a positive result (-1)^2 = 1
(a-b)(a^2+ab+b^2)
81