Answer:
she is faster
Step-by-step explanation:
first find how long sister takes to walk 1 mile - if she walks 2 miles in 1 hour she'll take less time to walk 1 mile, 2/2 = 1 mile
and 60mins/2 = 30mins
so sister walks 1 mile in 30 minutes and she walks 1 mile in 20 mins so she is faster by 10 mins
hope this helps :)
