Task 1. Given the numbers

$$
A=1+3+5+\ldots+99 \text { and } B=2+4+6+\ldots+100
$$

Which number is greater and by how much?
Solution. Each element in $B$ is 1 greater than the elements in $A$. Both $A$ and $B$ have 50 elements. Therefore, the sum of $B$ is greater, and by 50.