If a is a positive integer, and if the units digit of a^2 is 9 and the units digit of (a+1)^2 is 4, what is the units digit of (a+2)^2?  Choices:  A) 1  B) 3  C) 5  D) 6  E) 14
For unit digit of a^2 to be 9...unit digit of a has to be 3 or 7...   Now for unit digit of (a+1)^2 to be 4..unit digit of a has to be 1 or 7....   From the above two conditions, unit value of a has to be 7, which will satisfy both the conditions...   Now id unit digit of a is 7, unit digit of (a+2)^2 hast to be 1.   1NSWER:1
<result>A</result>
If a is a positive integer, and if the units digit of a^2 is 9 and the units digit of (a+1)^2 is 4, what is the units digit of (a+2)^2?