Question

Please, I need help on the 3rd question.
https://postimg.org/image/ezus5j3qv/

Answer 1

The pattern is (on the denominator) 1²,2²,3²,and so on... On the numerator is 1,3,5,7... , and the number of terms that appears is the same of the denominator without being squared.

Answer 2

The sum of the numbers with the same denominator will always result in 1

Answer 3

So, for the (1) question I found a50 = 9/100
And for the (2) question I found the sum = 37/4