From the answer choices below, select values that could work for the u

Question

From the answer choices below, select values that could work for the units digit of x and the units digit of  x^{14}

GmatTest2026 · Answer

Solution:

By applying the cyclicity concept, the only option that works for the unit's digit of x is 5, and  x^{14}  is 5 only.

lisahoang1301 · Answer

To determine the unit digits of x and  x^{14} , I think the quick way is to look at each option:
 
 If x=2, then its unit digits pattern follows the four-number pattern 2-4-8-6
Then unit digits of  x^{14}  is 4 --> No option for 4 
 If x=3, then its unit digits pattern follows the four-number pattern 3-9-7-1
Then unit digits of  x^{14}  is 9 --> No option for 9 
   If x=5, then its unit digits will always be 5, regardless of any positive integer powers of 5
Then unit digits of  x^{14}  is 5 --> Correct Answer   
 If x=7, then its unit digits pattern follows the four-number pattern 7-9-3-1
Then unit digits of  x^{14}  is 9 --> No option for 9 
 If x=8, then its unit digits pattern follows the four-number pattern 8-4-2-6
Then unit digits of  x^{14}  is 4 --> No option for 4

From the answer choices below, select values that could work for the u

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Units digit of x	Units digit of \(x^{14}\)
		2
		3
		5
		7
		8

GMAT Two-part Analysis (TPA) Questions

From the answer choices below, select values that could work for the u

Prep Toolkit

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