Question 583087
1.5 hrs just by looking at the problem
very simple 
if shes going 40 miles in 1 hour then in 1 hour shes traveled 40 miles so 40 from 60 is 20 miles left to go
20 is exactly half of the miles so if she is driving only half the distance its half the time too so 1 and 1 half hours or 1.5hrs
once you recognize this and it clicks these types of problems wont take u more then 5 secs to answer.