Question 497593
For 2 hrs the plane speed is 
{{{ 600 - 50 = 550 }}} mi/hr
In 2 hrs, the plane goes
{{{ d = 550*2 }}}
{{{ d = 1100 }}} mi
During the next hour, the plane travels
{{{ d = 600*1 }}}
{{{ d = 600 }}} mi
It's total distance traveled is 
{{{ 1100 + 600 = 1700 }}} mi
The answer is (c)