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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. √ 625
A^2 + 2ab + b^2
25
= the cube root of 8 = 2
169

2. 16^2
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
1024
256
27

3. √ 4
A^2 - 2ab + b^2
2
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
12.50%

4. 2^10
1024
Multiply the exponents 7^2(^3) = 7^6
(A+B)(A-B)
512

5. 1/8
3125
2
12.50%
Add the exponents and keep the base 7^3 x 7^5 = 7^8

6. 5^3
A^2 + 2ab + b^2
125
169
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4

7. 1/20
5%
32
169
...yields a smaller result (1/2)^2 = 1/4

8. 2^7
Add the exponents and keep the base 7^3 x 7^5 = 7^8
(a+b)(a^2-ab+b^2)
128
27

9. raising a fraction between zero and 1 to a power...
(a+b)(a^2-ab+b^2)
...yields a smaller result (1/2)^2 = 1/4
169
13

10. 17^2
= the square root of 9 = 3
1024
289
324

11. Express 9^1/2 as a radical
= the square root of 9 = 3
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
2.23
A^2 + 2ab + b^2

12. 14^2
(a-b)(a^2+ab+b^2)
1024
196
...yields a negative result (-1)^57 = -1

13. Prime Numbers between 1 - 100 (total of 25)
Take the reciprocal of the base and change the sign of the exponent (2)^-2 = 1^2/2^2 = 1/4
40%
{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}
225

14. 11^2
12.50%
121
243
A^2 - 2ab + b^2

15. to divide powers with the same base...
A^2 - 2ab + b^2
Subtract the exponents and keep the base the same 4^5/4^2 = 4^3
75%
16

16. 13^2
25%
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
8.33%
169

17. 6^5
256
7776
= the square root of 9 = 3
16.67%

18. 3^5
Add the exponents and keep the base 7^3 x 7^5 = 7^8
243
256
361

19. Simplifying a root
64
...yields a smaller result (1/2)^2 = 1/4
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
256

20. √ 5
121
2.23
(a+b)(a^2-ab+b^2)
8

21. 3/4
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
75%
1296
A^2 + 2ab + b^2

22. A^2-B^2
64
(A+B)(A-B)
128
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120

23. 2^4
Multiply the exponents 7^2(^3) = 7^6
128
16
50%

24. 7/8
A^2 - 2ab + b^2
4
1296
87.50%

25. 2^8
324
2.23
144
256

26. 15^2
1024
1296
1024
225

27. 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
64
2.449
8

28. Multiples of 15
15 - 30 - 45 - 60 - 75 - 90 - 105 - 120
1024
50%
256

29. 1/12
16
144
8.33%
243

30. 5^4
1.73
256
...yields a smaller result (1/2)^2 = 1/4
625

31. 1/6
16.66%
512
2
A^2 - 2ab + b^2

32. 3^4
81
(A+B)(A-B)
361
13

33. 1/5
20%
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
13
12.50%

34. 2^5
128
216
32
40%

35. 19^2
40%
12.50%
361
16.66%

36. to multiple powers (or raise a power to a power)
Multiply the exponents 7^2(^3) = 7^6
A^2 - 2ab + b^2
216
1024

37. a negative number raised to an odd power...
324
...yields a negative result (-1)^57 = -1
1.41
...yields a smaller result (1/2)^2 = 1/4

38. 2^6
40%
32
64
2.23

39. √25+16 = √41
You cannot simplify this one
= the cube root of 8 = 2
Add the exponents and keep the base 7^3 x 7^5 = 7^8
2.23

40. a^3-b^3
8.33%
(a-b)(a^2+ab+b^2)
625
...yields a positive result (-1)^2 = 1

41. Multiples of 8
1024
196
8 - 16 - 24 - 32 - 40 - 48 - 56 - 64 - 72 - 80 - 88 - 96 - 104 - 112 - 120
You cannot simplify this one

42. Multiples of 12
1296
25%
12 - 24 - 36 - 48 - 60 - 72 - 84 - 96 - 108 - 120
256

43. 2^3
1.73
40%
...yields a smaller result (1/2)^2 = 1/4
8

44. 2^2
2
8
4
256

45. Examples of roots simplification
289
√25.16 = √25 . √16 = 5.4 - √50 . √18 = √50.18 = √900 = 30 - √144:16 = √144 : √16 = 12/4 = 3
8.33%
7776

46. a^3+b^3
16.67%
64
= the cube root of 8 = 2
(a+b)(a^2-ab+b^2)

47. √ 6
25
2.449
83.33%
128

48. 1/2
27
64
50%
1296

49. 6^4
64
You cannot simplify this one
1296
144

50. (a+b)^2 =
83.33%
A^2 + 2ab + b^2
243
7776