Answer:
The answer is 71 miles
Step-by-step explanation:
According to the decimal rule, the Monday's 12.3 will be rounded off to 12,Tuesday 14.1 will be rounded off to 14, Wednesday 17.7 will be rounded off to 18 as .7 is greater than .5,Thursday 11.8 is rounded off to 12 and Friday to 15
To calculate how far she biked in all in five days we add all the distances she covered every day.So,
12 miles+14 miles+18 miles+12 miles+15 miles= 71 miles.