Question 4
Let $X$ and $Y$ be the following sums of arithmetic sequences: $$
\begin{aligned} X &= 10+12+14+\cdots+100,\\ Y &= 12+14+16+\cdots+102. \end{aligned}
$$ What is the value of $Y - X?$
\begin{aligned} X &= 10+12+14+\cdots+100,\\ Y &= 12+14+16+\cdots+102. \end{aligned}
$$ What is the value of $Y - X?$