Question 1043092
Use the formula {{{d = rt}}} for the distance travelled by an object with speed r for an interval of time t.

Let the real speed of the train be r.  Suppose the the distance to the destination is d.  5/8 of its real speed is {{{(5/8)r}}}, 
and the time travelled would be {{{ d/((5/8)r) = (8/5)(d/r)}}}.  Hence,

{{{ (8/5)(d/r) - d/r = 6/5}}},

since 1 hour, 20 minutes is {{{1&1/5 = 6/5}}} hours.

===> {{{(3/5)(d/r) = 6/5}}}  ===> {{{d/r = 2}}}, or d = 2r.

===> The actual time taken to reach the destination is {{{t = d/r = (2r)/r = highlight(2)}}} hours.