A workshop's output this year is 140% of last year's. Next year's plan is set at 80% of this year's output. Next year's planned output is what per cent of last year's?

Take last year's output as 100. This year = 140, and next year's plan = 80% of 140 = 112, so the plan is 112% of last year's output. As factors, $1.40\times 0.80=1.12$. 220% adds the two figures and 60% subtracts them; neither works, because the 80% is taken OF this year's output, so the two must multiply. 120% takes the 80% as '20 less' and knocks 20 points off the 140 - but 20% of 140 is 28, not 20.