Question 555001
Let {{{t}}} = time in hours for 1st flight
Let {{{d}}} = distance between towns in km
Equation for A to B:
{{{ d = 800t }}}
Equation for B to A:
{{{ d = 1000*( t - 1.5 ) }}}
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Bt substitution:
{{{ 800t = 1000t - 1500 }}}
{{{ 200t = 1500 }}}
{{{ t = 7.5 }}} hrs
and, since
{{{ d = 800t }}}
{{{ d = 800*7.5 }}}
{{{ d = 6000 }}}
The distance between the towns is 6,000 km
check:
{{{ d = 1000*( t - 1.5 ) }}}
{{{ d = 1000*( 7.5 - 1.5 ) }}}
{{{ d = 1000*6 }}}
{{{ d = 6000 }}}
OK