Novemberish

a) A four digit number (in base 10) aabb is a perfect square. Discuss ways of systematically finding this number. (b) Prove that 11^{10}-1 is divisible by 100.

Problem



Image
Novemberish

(a) A four digit number (in base $10$) $aabb$ is a perfect square. Discuss ways of systematically finding this number.

(b) Prove that $11^{10}-1$ is divisible by $100$.