5. When travelling from London to Edinburgh by train, you pass a sign saying 'Edinburgh 200 miles'. Then, $3 \frac{1}{2}$ miles later, you pass another sign saying 'Half way between London and Edinburgh'.
How many miles is it by train from London to Edinburgh?
A 393
B $396 \frac{1}{2}$
C 400
D $403 \frac{1}{2}$
E 407
5. A By train, the distance in miles of the second sign from Edinburgh is $200-3 \frac{1}{2}$. This sign is halfway between London and Edinburgh, so the distance in miles between the two cities is $2\left(200-3 \frac{1}{2}\right)=400-7=393$.