A slug and a snail decided to settle a long-standing argument as to who was the best sprinter. So they planned a race between two stones set a distance D cm apart. Said the slug to the snail:

- "Since I'm slimier than you, I intend to start T seconds before you".

- "In that case," said the snail, who was rather slow, "I'm going to give you X cm start" (the snail stays at the stone, and the slug starts from X cm ahead.)

It didn't matter. The slug, who could move at speed V cm/sec, was only half as fast as the snail. The result was a dead heat, t seconds after the slug set off.

Now, D, t, T, V and X were all whole numbers from 1 to 10 inclusive, no two numbers being the same.

How long did it take the snail to reach the finish?