Taking into account the change of units, Fred swam 12040 meters in 2 weeks.
Rule of three
The rule of three is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other) , the direct rule of three must be applied.
To solve a direct rule of three, the following formula must be followed, being a, b and c known data and x the variable to be calculated:
a ⇒ b
c ⇒ x
So: x= (c×b)÷a
The direct rule of three is the rule applied in this case where there is a change of units.
Meters Fred swam
To perform in this case the conversion of units, you must first know that 1000 m = 1 km. So, if 1 km is 1000 m, how many meters equals 0.86 kilometers?
1 kilometer ⇒ 1000 meters
0.86 kilometers ⇒ x
So:
x= (0.86 kilometers×1000 meters)÷1 kilometers
Solving:
x= 860 meters
Fred swam 860 meters each day in 2 weeks. Considering that 2 weeks has 14 days, then during those 2 weeks Fred swam:
Distance= 860 meters× 14 days
Distance= 12040 meters
In summary, Fred swam 12040 meters in 2 weeks.