Filling Morecambe Bay
"It would take 20 million years to fill Morecambe Bay from a bath tap". What does this imply is the approximate capacity of Morecambe Bay?
Age
11 to 14
Challenge level
Problem
A notice on Morecambe Promenade reads: "It would take $20$ million years to fill Morecambe Bay from a bath tap." Assuming that the flow from a bath tap is $6$ litres per minute, what is the approximate capacity of Morecambe Bay, in litres?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
Student Solutions
Answer: About $60,000,000,000,000$ litres
$6$ litres per minute
$6\times60$ per hour
$6\times60\times24$ per day
$6\times60\times24\times365.25$ per year
$6\times60\times24\times365.25\times20,000,000$ total
This can be approximated by:
$\begin{align}6 \times 60 \times 20 \times 400 \times 20,000,000 =& 2,880,000\times 20,000,000\\
\approx& 3,000,000 \times 20,000,000\\
&=60,000,000,000,000\end{align}$