Question 878316
note: how long (in min) did he take to finish <u>the first half</u>? 
{{{x/2 + x = 2hr}}}
   x + 2x = 4
    3x = 4
     x = 4/3, 1hr, 20min was the time for the 'second' half
the first half is x/2
80min/2 = 40min, for the first half.