Democratic presidential candidate and former Secretary of State Hillary Clinton shakes hands with rival candidate and U.S. Senator Bernie Sanders during the first official Democratic candidates debate of the 2016 presidential campaign in Las Vegas on Oct. 13, 2015. (Lucy Nicholson/Reuters)

College affordability got a few minutes during the Democratic presidential debate Tuesday night, with front-runner Hillary Clinton and Sen. Bernie Sanders (I-Vt.) promoting their competing ideas to lower student debt and eliminate tuition costs at public colleges and universities.

Clinton, the former secretary of state, wants to create an incentive program that would provide federal money to states that guarantee “no-loan” tuition at four-year public universities and community colleges.

“As a young student in Nevada said to me, ‘The hardest thing about going to college should not be paying for it,’” Clinton said. She said she hopes to allow all interested students to attend a public university or college “tuition free” but would require them to work at least 10 hours a week.

Clinton has said she wants to fund her plan, which she estimates would cost $350 billion over 10 years, by closing tax loopholes. The money would be sent to states to increase their investment in public colleges and universities and to lower the interest rates on student loans. States that enroll a high number of low- and middle-income students would receive more money, as would those states where public universities reduce expenses.

Sanders wants to tax Wall Street transactions and use the money to make public colleges and universities free to anyone.

“This is the year 2015,” Sanders said. “A college degree today is the equivalent of what a high school degree was 50 years ago. ... We don’t need a complicated system, which is what the secretary is talking about. I pay for my program through a tax on Wall Street speculation, which will not only make colleges and universities tuition-free, it will substantially lower college debt.”

Sanders and Clinton, meanwhile, both want Congress to lower interest rates on federal student loans. Sanders, Clinton and former Maryland Gov. Martin O’Malley all want to let students and parents refinance federal loans at lower interest rates.

None of the candidates talked about ways to increase college completion rates, which hover around 60 percent.

The candidates also did not address K-12 education issues during the debate Tuesday night.