Question 159
a) Show that the last two digits of $1038^2$ are 4.
b) Show that there are infinitely many perfect squares whose last three digits are 4.
c) Prove that there is no perfect square whose last four digits are 4.
b) Show that there are infinitely many perfect squares whose last three digits are 4.
c) Prove that there is no perfect square whose last four digits are 4.