Let $P$ be the set of $42^{\text{nd}}$ roots of unity, and let $Q$ be the set of $70^{\text{th}}$ roots of unity. How many elements do $P$ and $Q$ have in common

What is the order of magnitude for the number of liters in a large bottle of soda served at a party

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Solve each quadratic equation by factoring and using the zero product property. x^2 - 8x + 30 = 3x