There are 1500/25 = 60 lengths of 25cm
A 15k marathon is just 15 kilometers, or roughly 9.3 miles.
1.5 kilometers=0.932056788 miles
A 5K is 3.1 miles, so I think a 15K would be 9.3.....
9.3 (9.32057) miles.
33.0693393 so about 33 pounds.
With appropriate training, you may be able to run a 15K.
15 kilometers = 9.321 miles
31 lengths.
15,000
The greatest common factor of 18k and 15k is 3k.
It means kilo which is 1000 and 15k is 15*1000 = 15000