BTGmoderatorDC wrote:When the integer n is divided by 17, the quotient is x and the remainder is 5. When n is divided by 23, the quotient is y and the remainder is 14. Which of the following is true?
(A) 23x + 17y =19
(B) 17x -23y = 9
(C) 17x +23y =19
(D) 14x + 5y = 6
(E) 5x - 14y = -6
Here's a useful rule:
If A divided by B equals C with remainder D, then it's also true that BC + D = A (this is an important GMAT concept)
Example: Since 32 divided by 5 equals 6 with remainder 2, then it's also true that (5)(6) + 2 = 32
Now onto the question:
We're told that "
when n is divided by 17, the quotient is x and the remainder is 5," which means 17x + 5 = n
We're also told that "
when n is divided by 23, the quotient is y and the remainder is 14," which means that 23y + 14 = n
Now, if
17x + 5 equals
n AND
23y + 14 also equals
n, it must be true that
17x + 5 =
23y + 14
If we rearrange the terms of this equation, we get 17x - 23y = 9
Answer: B
Brent Hanneson - Creator of GMATPrepNow.com
