Question 756905
Assuming morning drive speed was x mph John has driven 11 hrs at speed x and 3 hours at speed (x+10).

Hence forming equation for total distance driven, we have
x.11 + (x+10).3 = 590
i.e. 11x +3x +30= 590
i.e. 14x +30 -30= 590 -30
i.e. 14x        = 560
i.e.   x        = 560/14 = 40 mph