robert 数学答疑中2002-12中的一道题

xmwangyu

robert 数学答疑中2002-12中：

1.k is a 2-digit positive integer, the value of k is 6 times of the unit digit, what is the value of k?
(1). the ten digit is 4 greater than unit digit.
(2). the sum of the two digits is a two-digit integer.
确认: .: D
确认: 感觉题有些怪
解:
由题知:令k=10x+y,则 10x+y=6y => 2x=y

我感觉有问题。应该是b.
条件（1）x=4+y与2x=y，得x=-4. tens digital can't be -4.

条件(2): x+y>=10, x>=10/3. 结合2x=y, x=4,y=8. k=48.

tongxun

你的是正确的/