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QOTD#17 If x is divisible by 78, which of the following must
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22 Nov 2016, 16:41
22 Nov 2016, 16:41
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5% (01:04) correct
94% (01:17) wrong based on 51 sessions
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If x is divisible by 78, which of the following must be divisible by x?
Indicate all possible values.
A. \(\frac{x}{78}\)
B. \(x\)
C. \(x+78\)
D. \(78-x\)
E. \(78x\)
F. \(78x+78\)
Indicate all possible values.
A. \(\frac{x}{78}\)
B. \(x\)
C. \(x+78\)
D. \(78-x\)
E. \(78x\)
F. \(78x+78\)
Drill 4
Question: 12
Page: 295
Question: 12
Page: 295
Re: QOTD#17 If x is divisible by 78, which of the following must
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12 Jun 2017, 09:06
12 Jun 2017, 09:06
5
sandy wrote:
Explanation
There are variables in the answer choices, so Plug In. Try x = 78. You can eliminate choices (A) and (D). Now try a weird number: 0. Eliminate choice (G). Try one more number: 156, which is double 78. This time you can eliminate choices (C) and (E). A number is divisible by itself and a multiple of a number is divisible by that number, so the correct answers are choices (B) and (F).
Hence options B and F are correct.
There are variables in the answer choices, so Plug In. Try x = 78. You can eliminate choices (A) and (D). Now try a weird number: 0. Eliminate choice (G). Try one more number: 156, which is double 78. This time you can eliminate choices (C) and (E). A number is divisible by itself and a multiple of a number is divisible by that number, so the correct answers are choices (B) and (F).
Hence options B and F are correct.
Your solution is Incorrect.
Let me explain this ==>
Here question is asking us => "Which of the following is divisible by x"
Option 1) x/78 => Let x=78 => x/78 = 1 and 1 is not divisible by 78 => REJECT.
Option 2) x/x =1 => Accept
Option 3) (x+78)/x => 1+(78/x) => Is x= 78 => OK else if x=78*2 => Not OK => REJECT.
Option 4) (78-x)/x => 78/x - 1 => If x=78 => OK else if x=78*2 => Not OK => REJECT.
Option 5) 78x/x => 78 => ALWAYS an integer.=> ACCEPT
(You cannot plus in x as zero as division by zero is considered to be illegal on the GRE. You can take any value of x => and this will always be 78 which is an integer)
Option 6) (78x +78)/x => 78 + 78/x => If x = 78 => OK else if x=78*2 = Not OK => REJECT.
Hence the Correct answer choices must be B and E
Smash that B and E
Regards
Stone Cold
General Discussion
Re: QOTD#17 If x is divisible by 78, which of the following must
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22 Nov 2016, 16:44
22 Nov 2016, 16:44
Expert Reply
Explanation
There are variables in the answer choices, so Plug In. Try x = 78. You can eliminate choices (A) and (D). Now try a weird number: 0. Eliminate choice (G). Try one more number: 156, which is double 78. This time you can eliminate choices (C) and (E). A number is divisible by itself and a multiple of a number is divisible by that number, so the correct answers are choices (B) and (F).
Hence options B and F are correct.
There are variables in the answer choices, so Plug In. Try x = 78. You can eliminate choices (A) and (D). Now try a weird number: 0. Eliminate choice (G). Try one more number: 156, which is double 78. This time you can eliminate choices (C) and (E). A number is divisible by itself and a multiple of a number is divisible by that number, so the correct answers are choices (B) and (F).
Hence options B and F are correct.
