It all depends on several factors, such as the size, how ripe it is and the kind. You also have to see if the watermelon has been chemically produced to have no seeds.
in a watermelon...
Watermelon plants are easily grown from seed.
how to plant a watermelon tree is first,you buy a watermelon,then you open the watermelon,then there are many seeds inside, take out one of the seed and put it in the soil,water it,and the next day,it grew!
Watermelon
They grow from seed, to seedling, to adult in the same manner.
Through human and other animals who eat watermelon fruits
Forty.
huh
a watermelon
They grow from seed, to seedling, to adult in the same manner.
seven days
A watermelon seed.