Washington (CNN) -- When Paul Ryan struggled to explain a budget-balancing timeline under Mitt Romney, he highlighted the difficulty of trying to run a substantive campaign without being too specific.

While Ryan's interview Tuesday with Fox News' Brit Hume was no Sarah Palin-Katie Couric moment, the Republican vice presidential candidate's discomfort in answering when Romney's proposal would balance the budget was evident.

Ryan, a seven-term congressman from Wisconsin and chairman of the House Budget Committee, said he was unsure when Romney's proposals would balance the federal budget. Romney's plans say he would "put the federal government on a course toward a balanced budget" but does not say when.

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Hume repeatedly pressed Ryan on the question of "when" Romney's budget would balance.

Hume: "The budget plan you're now supporting would get to balance when?"

Ryan: "Well, there are different -- the budget plan that Mitt Romney is supporting gets us down to 20% of GDP (gross domestic product) government spending by 2016. That means get the size of government back to where it historically has been. What President Obama has done is he brought the size of government to as high as it hasn't been since World War II. We want to reduce the size of government to have more economic freedom."

Hume: "I get that. What about balance?"

Ryan: "I don't know exactly what the balance is. I don't want to get wonky on you, but we haven't run the numbers on that specific plan. The plan we offer in the House balances the budget. I'd put a contrast. President Obama, never once, ever, has offered a plan to ever balance the budget. The United States Senate, they haven't even balanced, they haven't passed a budget in three years."

Answer this series of questions:

1. Who had a hard time explaining budget?
2. Who was he under at the time?
3. What specifically did he cite were his problems in running the campaign?
1. Paul Ryan
2. Mitt Romney
3. balancing a budget