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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
2
144
5%
87.50%

2. √25+16 = √41
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
1.41
You cannot simplify this one
8

3. 6^5
256
7776
(a+b)(a^2-ab+b^2)
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3

4. 2^2
...yields a negative result (-1)^57 = -1
4
Add the exponents and keep the base 7^3 x 7^5 = 7^8
16.67%

5. Express 9^1/2 as a radical
= the square root of 9 = 3
64
83.33%
289

6. 5^4
...yields a positive result (-1)^2 = 1
625
64
12.50%

7. 3^3
144
27
3125
...yields a negative result (-1)^57 = -1

8. 5/6
16.67%
12.50%
20%
83.33%

9. 7/8
50%
1024
87.50%
...yields a smaller result (1/2)^2 = 1/4

10. Express 8^1/3 as a radical
169
= the cube root of 8 = 2
225
20%

11. 2^10
1024
...yields a smaller result (1/2)^2 = 1/4
625
Multiply the exponents 7^2(^3) = 7^6

12. 5^3
4
125
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
= the cube root of 8 = 2

13. Prime Numbers between 1 - 100 (total of 25)
1.73
...yields a positive result (-1)^2 = 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
{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}

14. to divide powers with the same base...
8.33%
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
12.50%
...yields a negative result (-1)^57 = -1

15. 1/4
196
16.66%
25%
Add the exponents and keep the base 7^3 x 7^5 = 7^8

16. to multiple powers with the same base...
12.50%
Add the exponents and keep the base 7^3 x 7^5 = 7^8
32
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

17. Simplifying a root
20%
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
25

18. 6^3
216
625
Add the exponents and keep the base 7^3 x 7^5 = 7^8
2.23

19. (a-b)^2 =
1024
64
40%
A^2 - 2ab + b^2

20. 2^4
12.50%
128
16.66%
16

21. √ 5
...yields a negative result (-1)^57 = -1
2.23
225
5%

22. 15^2
Multiply the exponents 7^2(^3) = 7^6
2.449
256
225

23. √ 6
40%
13
2.449
1024

24. 2^5
125
243
16
32

25. 1/6
{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}
8
13
16.67%

26. 2^9
A^2 - 2ab + b^2
3125
512
256

27. √ 4
13
2
3125
7776

28. 1/20
8
1296
8.33%
5%

29. 3^4
324
81
289
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120

30. to multiple powers (or raise a power to a power)
25%
83.33%
1296
Multiply the exponents 7^2(^3) = 7^6

31. 1/2
13
50%
83.33%
216

32. a negative number raised to an odd power...
512
...yields a negative result (-1)^57 = -1
225
Add the exponents and keep the base 7^3 x 7^5 = 7^8

33. 4^4
25%
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
(a-b)(a^2+ab+b^2)
256

34. √ 2
16.67%
1.41
16
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120

35. Examples of roots simplification
216
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
225
121

36. a^3+b^3
87.50%
(a+b)(a^2-ab+b^2)
125
64

37. 6^4
1296
128
81
7776

38. a negative number raised to an even power...
...yields a positive result (-1)^2 = 1
1296
16.66%
...yields a smaller result (1/2)^2 = 1/4

39. 4^3
256
64
289
216

40. 17^2
3125
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
289
...yields a negative result (-1)^57 = -1

41. √ 3
1.73
324
75%
16.67%

42. 14^2
216
...yields a negative result (-1)^57 = -1
13
196

43. 1/12
169
81
2.23
8.33%

44. A^2-B^2
(A+B)(A-B)
125
2.23
3125

45. 2^3
16
8
16.67%
You cannot simplify this one

46. 16^2
81
256
125
= the cube root of 8 = 2

47. 11^2
(a+b)(a^2-ab+b^2)
= the cube root of 8 = 2
121
169

48. √ 169
4
= the cube root of 8 = 2
8
13

49. what happens when an exponent is negative?
{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%
50%
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

50. 1/8
2.449
512
1.41
12.50%