Cross-country (1)

A cross-country event for all is organized by a sports association. The length of the course is 5 000 m for adults, but it is reduced by 50% for youngsters aged between 16 and 18.

In order to calculate the distance that youngsters aged between 16 and 18 have to cover you can:

subtract 50 m to the total distance covered by adults.
subtract half of the total distance covered by adults.
divide by 2 the total distance covered by adults.
multiply by 0.5 the total distance covered by adults.
divide by 50 the total distance covered by adults.