alleryWhich digit can never be the units digit of a square number?
A7
B1
C6
D9
Answer & Solution
Correct answer: A. 7
1. Squares end in 0, 1, 4, 5, 6 or 9.
2. They never end in 2, 3, 7 or 8.
3. So 7 is impossible.
_Source: syllabus Mathematics, Chapter 6, Squares and Square Roots._
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