Q.How much time would it take to distribute one Avogadro number of wheat grains, if 1010 grains are distributed each second ?

Step 1 – Set up the division

Step 2 – Substitute

Step 3 – Convert seconds to years for a physically meaningful answer

$1\ \text{year} \approx 365\ \text{days} \times 24\ \text{h} \times 3600\ \text{s} = 3.154\times10^{7}\ \text{s}$ …

Simple division: time = (total number of items, here Avogadro's number) ÷ (rate). Convert the resulting huge number of second …

• Misreading the rate as $10\times10=100$ grains/s instead of $10^{10}$ grains/s (a notation/scientific-notation slip).
• Stopping at the answer in seconds without converting to a comprehensible unit (years) — the point of the problem is to show how astronomically l …