13.What is tens digit of the twodigit number x?
1) units digit of x is 7
2) tens digit of 2x is 5
tens digit please help!
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(1) is clearly not sufficient; no information about the tens digit of x.13.What is tens digit of the twodigit number x?
1) units digit of x is 7
2) tens digit of 2x is 5
(2) tells us that x is either between 25 and 29 inclusive or between 75 and 79 inclusive. Not sufficient because we get two values for the tens digit of x: 2 or 7.
(1&2) tells us that x is either 27 or 77. Still not sufficient as the tens digit of x could be either 2 or 7.
The correct answer is E.
Rey Fernandez
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Manhattan GMAT
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Manhattan GMAT

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Ans. E
=>One's digit is 7 gives no clue about ten's digit (Ignore)
=> Ten's digit of 2x is 5 gives nothing again .. 2x it can be any number of the form _5_.
Coming 1 and 2 we have x= _7 and 2x=_54
2x can be 154 or just 54 making x 77 or 27 respectively.
No clear solution.
=>One's digit is 7 gives no clue about ten's digit (Ignore)
=> Ten's digit of 2x is 5 gives nothing again .. 2x it can be any number of the form _5_.
Coming 1 and 2 we have x= _7 and 2x=_54
2x can be 154 or just 54 making x 77 or 27 respectively.
No clear solution.