Among 1,250 patients with young-onset colorectal cancer (mean age 42.8 ± 6.0 years; 45.4% female), 46.3% had rectal cancer. Emotional concerns were most common (41.0%), followed by physical (36.1%), ...

Place any number of dots on a two-dimensional plane—say, a piece of paper—and measure the distance between each pair. If you rearrange the dots, how many pairs could be positioned exactly the same ...