1 votes 1 votes Let $U_{1}\supset U_{2} \supset...$ be a decreasing sequence of open sets in Euclidean $3$-space $\mathbb{R}^{3}$. What can we say about the set $\cap U_{i}$ ? It is infinite. It is open. It is non-empty. None of the above. Linear Algebra tifrmaths2015 linear-algebra non-gate + – makhdoom ghaya asked Dec 20, 2015 makhdoom ghaya 330 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.