The right answer, of course, is that prices continue to rise, but not so fast. The answer the pollsters got - when they could persuade any adult to agree to being quizzed on their maths at all - frequently arrived at the right conclusion, but for the wrong reason. "Prices should go down," many are said to have answered, "but of course they won't because they only ever go up, don't they?"
Governments face the same hardbitten cynicism whenever they claim to have improved the funding for a popular public service. The same protestations of government generosity have too often in the past accompanied painful cuts at the grassroots, disillusioned demonstrations and obfuscation about exactly where the money went. The current year is a case in point: fewer than half the local education authorities passed down to schools the full increase in the amount the Government said they should be spending.
The extra #163;1 billion which Labour carved out of contingency funds for UK education next year is not likely to prove any exception either. Education Secretary David Blunkett made it abundantly clear that the new money had better be used to support school improvement - or else. And local government is showing signs that it realises that the appropriate increases must be passed on.
But both have a long way to go to convince teachers, governors and parents that a new era in school funding has really dawned. For many, the evidence of further cuts is all too plain.
The reasons are manifold. Welcome though Labour's largesse was, it is quite modest when set against the growth in demand and the legacy of years when funding did not match the combined pressures of inflation and rising pupil numbers. The extra #163;1bn barely made good the cuts planned for 1998-99 by the previous government.
England's #163;835 million share of that #163;1bn is likely to be swallowed up by the additional pupils expected in schools, the extra teachers needed if Labour's promises on infant class sizes are to be realised, the hangover cost of last year's pay award, and the new costs of this year's.
Many authorities are no longer able or willing to go on favouring education at the expense of other services either. The cutbacks and productivity improvements which other council services have had to make are increasingly contrasted with the relatively modest improvements provided by the schools service.
Most councils still spend more on education than their standard spending assessment (SSA) - the amount the Government calculates they should spend. But education expenditure above SSA fell from 4.5 per cent of council spending on education three years ago to 3.2 per cent this year. In 1993-94, 15 councils spent below their SSA; this year 28 planned to do so. Labour's commitment to fairer funding also spells cuts for authorities which lose out to the Government 's new priorities. So it is no surprise to find the National Governors' Council writing to David Blunkett to say that it sees no sign of the increases coming through in school budgets; the NGC is strong in the shires, which have lost out to urban areas under the new dispensation.
Labour may have made education an exceptional case in its own terms. But it was motivated in part, at least, by a wish to appease the broadly-based,active and therefore electorally important education lobby; to convince the public that in government it has put its money where its mouth used to be.
Meanwhile, largely-Labour local government is finding that the "blame the Government" consensus that it nurtured under the Conservatives no longer answers. If education authorities want to be left to administer education spending locally, they need to present a much stronger case not only to central Government, but to headteachers, governors, parents or whoever else the Government wants to convince.