Question

11 supra 13 + 1111 supra 1313 +111111 supra 131313 + 11111111 supra 13131313 =....

Answer 1

$\dfrac{11}{13}+\dfrac{1111}{1313}+\dfrac{111111}{131313}+\dfrac{11111111}{13131313}=\dfrac{11}{13}+\dfrac{11\cdot 101}{13\cdot 101}+\dfrac{11\cdot10101}{13\cdot 10101}+\dfrac{11\cdot1010101}{13\cdot 1010101}=\\\\=4\cdot\dfrac{11}{13}=\dfrac{44}{13}.$

Green eyes.