A man covers two-third of a certain distance at the speed of 70 km/h and the rest at the speed of 50 km/h. It takes him \({6\frac{4}{5}}\) hours for the whole journey. At a speed of 56 km/h, in what time will he be able to cover the entire distance?
1
7 hours
2
\( {8\frac{1}{3}}\) hours
3
\( {7\frac{1}{2}}\) hours
4
More than one of the above
5
None of the above