Arithmatical - Odd Man Out and Series
DIRECTIONS : Find out the wrong number in the series
6. |
3, 7, 15, 27, 63, 127, 255 |
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A. 7 |
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B. 15 |
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C. 27 |
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D. 63 |
Solution |
27. |
Go on multiplying the number by 2 and adding 1 to it to get the next number. So 27 is wrong. |
|
7. |
2880, 480, 92, 24, 8, 4, 4 |
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A. 480 |
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B. 92 |
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C. 24 |
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D. 8 |
Solution |
92. |
Go on dividing by 6, 5, 4, 3, 2, 1 respectively to obtain the next number. Clearly, 92 is wrong. |
|
8. |
445, 221, 109, 46, 25, 11, 4 |
|
A. 221 |
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B. 109 |
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C. 46 |
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D. 25 |
Solution |
46. |
Go on subtracting 3 dividing the result by 2 to obtain the next number. Clearly, 46 is wrong. |
|
9. |
7, 8, 18, 57, 228, 1165, 6996 |
|
A. 8 |
|
B. 18 |
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C. 57 |
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D. 228 |
Solution |
228. |
Let the given numbers be A, B, C, D, E, F, G. Then A, Ax1, Bx2+2, Cx3+3, Dx4+4, Ex5+5 ... and so on. are the required numbers. Clearly, 228 is wrong. |
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10. |
1, 3, 10, 21, 64, 129, 356, 777 |
|
A. 10 |
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B. 21 |
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C. 64 |
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D. 356 |
Solution |
356. |
Ax2+1, Bx3+1, Cx2+1, Dx3+1 and so on. So, 356 is wrong. |
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