1.73 is the answer >:-)............................
ANSWER:
d = 15
The swimmer swam 48 kilometres in 15 days.
STEP-BY-STEP EXPLANATION:
Let d = total no. of days the swimmer swam
Total no. of kilometres swam = 48
Average no. of kilometres swam daily = 3.2
THEREFORE:
3.2d = 48
d = 48 / 3.2
d = 15
So it can be easier to solve your problem
Zeros are:



Looks like only

and

are offered as answers, though.