Final answer:
The newsagent needs to sell 60 chocolate bars at 67p each to recuperate the initial investment of £40.20.
Step-by-step explanation:
To calculate how many chocolate bars the newsagent needs to sell to make his money back, we first need to find out how much each chocolate bar cost the newsagent and then how many bars they'd need to sell at 67p each to cover that cost.
The newsagent bought 100 chocolate bars for £40.20. To calculate the cost per chocolate bar, we divide the total cost by the number of bars: £40.20 / 100 bars = £0.402 per bar.
To recover the cost of one bar, the newsagent sells it for 67p. To find out how many bars need to be sold at 67p to make back the £40.20, we divide the total initial cost by the selling price per bar: £40.20 / £0.67 = 60 bars (rounded down to the nearest whole bar).
Therefore, the newsagent needs to sell 60 chocolate bars at 67p each to recover the initial cost of £40.20.