geoff: hannah dreier, thanks for your time and for sharing your reporting with us. ppreciate it. hannah: thank you. ♪ amna: we are mere weeks away from college basketball's march madness and, with it, billions of dollars' worth of wagers on the games. as more states legalize sports betting, paul solman reports on worries that some coeges are too involved in its promotion, a particular concern since, in all but four states, residents must be 21 years old to place a legal bet. this story is a partnership with the shirley povich center for sports journalism and the howard center for investigative journalism, both at the university of maryland's merrill college of journalism. >> i'm winning. then i feel like an idiot for not betting higher and betting more often. paul: saul malek, betting on sports through an online bookie at his texas college in 2017. saul: with my strategy, i can make hundreds of dollars in a minute. paul: once, says malek: saul i was up a few thousand credit that week, and i lost it all betting on someone in an individual tennis game. and i didn't eve