8) Three friends regularly go to the park to run: the first one every 10 days, the second one every 15 days, and the third one every 14 days. One Sunday they happen to run together. After how many Sundays will they meet at the park for the first time to run together again?
$\begin{array}{ll}\text { (A) } 22 & \text { (B) } 25\end{array}$
(C) 30
(D) 70
(E) never.
8) The answer is (C). The number of days after which they will run together again is given by the least common multiple of 10, 15, and 14, which is 210. The three friends will run together again after 210 days, which is after 30 weeks.