Question 598671
They are moving apart at the rate of {{{ 40 + 35 = 75 }}} mi/hr
Let {{{ t }}} = time for them to be {{{ 150 }}} mi apart 
{{{ 150 = r*t }}}
{{{ 150 = 75t }}}
{{{ t = 150/75 }}}
{{{ t = 2 }}}
They will be 150 mi apart in 2 hrs