What is the units digit of the number z?

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by GMATGuruNY » Sun Apr 28, 2019 2:53 am

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BTGmoderatorDC wrote:What is the units digit of the number z?

(1) 17 < z < 20
(2) 18 < z < 21
Statements combined:
Case 1: z=19, with the result that z is between both 17 and 20 and 18 and 21
In this case, the units digit of z is 9.
Case 2: z=18.1, with the result that z is between both 17 and 20 and 18 and 21
In this case, the units digit of z is 8.
Since the units digit can be different values, the two statements combined are INSUFFICIENT.

The correct answer is E.
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