Question 261782
"Ben leaves his house and walks to meet Anna. Anna leaves her house 30 minutes later and walks to meet Ben. Anna's average walking speed is 3mph and Ben's is 4 mph. When they meet, Ben has walked twice as far as Anna. Find the total distance they walked." 
I know the distance is 9 miles -- I need an explanation on how they got this answer. Thank you.

D distance = R rate * T time
D ben 30min = 4mph * 0.50 hours (30 minutes = 0.5 hrs)
D ben 30min = 2 miles
B Ben distance, A Anna distance
A = 3mph * t  (t time in hours)
B = 4mph * t

(4 * t) + 2 = 2 * (3 * t)
4t + 2 = 6t
2  = 2t
1 hour = t
D ben 1 hour = 4mph * 1 hour = 4 miles

Ben walked 6 miles.
And since Ben walked twice as far as Anna, Anna walked 3 miles.

Which is a total of 9 miles.