JJ2014 wrote:
For nonnegative integers x and y, what is the remainder when x is divided by y?
(1) x/y = 13.8
(2) The numbers x and y have a combined total of less than 5 digits
We need to determine the remainder when x is divided by y.
Statement One Alone:x/y = 13.8
We can rewrite statement one as:
x/y = 13 + 8/10
There are infinite possible values for the remainder when x is divided by y. That is because the remainder is the numerator of any equivalent fraction of 8/10. For example, the remainder can be 8 if x = 138 and y = 10, or it can be 16 if x = 276 and y = 20 (note: 276/20 = 13 + 16/20 = 13.8). Thus, statement one is not sufficient to answer the question.
Statement Two Alone:The numbers x and y have a combined total of less than 5 digits.
Statement two does not provide enough information to answer the question. For example, x can be 3 digits and y can be 1 digit, or x can be 2 digits and y can be 2 digits. Without knowing the exact values of x and y, statement two is not sufficient to answer the question.
Statements One and Two Together:From statement one, we know that x/y = 13.8 or x = 13.8y. Since x is at least 10 times as much as y, x has either one or two more digits than y. For example, if y = 10, then x = 138 (so x has one more digit than y); if y = 80, then x = 1,104 (so x has two more digits than y). Combining statement one with statement two, we see that either x has 3 digits and y has 1 digit or x has 2 digits and y has 1 digit.
Recall that x = 13.8y, and if y has 1 digit and x has 3 digits, a 1-digit number times 13.8 cannot yield a 3-digit whole number. Therefore, x must have 2 digits and y must be 1 digit. In that case, the only way to satisfy x = 13.8y is if y = 5 and x = 13.8(5) = 69. Hence, the remainder when x is divided y is 4 (69/5 = 13 + 4/5).
Answer: C
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