On a river, Q is the mid-point between two points P and R on the same bank of the river. A boat can go from P to Q and back in 12 hours, and from P to R in 16 hours 40 min. How long would it take to go from R to P?

• A. \(3\frac{1}{3}\;hr\)
• B. 5 hr
• C. \(6\frac{2}{3}\;hr\)
• D. \(7\frac{1}{3}\;hr\)