9. The world's fastest tortoise is acknowledged to be a leopard tortoise from County Durham called Bertie. In July 2014, Bertie sprinted along a $5.5 \mathrm{~m}$ long track in an astonishing 19.6 seconds.
What was Bertie's approximate average speed in $\mathrm{km}$ per hour?
A 0.1
B 0.5
C 1
D 5
E 10
9. C Bertie travelled $5.5 \mathrm{~m}$ in $19.6 \mathrm{~s}$, which is just less than one-third of a minute. So his average speed was approximately $16.5 \mathrm{~m}$ per minute, which is equal to $990 \mathrm{~m}$ in one hour, as $16.5 \times 60=990$. Now $990 \mathrm{~m}=0.99 \mathrm{~km}$, so Bertie's approximate average speed was $1 \mathrm{~km}$ per hour.