Question 535312
Sina went 40 km at 60 km/hr
{{{ 40 = 60*t }}}
{{{ t = 2/3 }}} hr
She was 15 min late for 11:15 appointment,
so she arrived at 11:30
If she left at 10:40, it will take her 35 minutes
to get there at 11:15
Let {{{s}}} be her average speed
{{{ 40 = s*(35/60) }}}
{{{ 35s = 40*60 }}}
{{{ 35s = 2400 }}}
{{{ s = 68.57 }}} km/hr average speed