Question 736483
Let {{{ p }}} = the speed of the plane in still air
Let {{{ w }}} = the wind speed
{{{ p + w }}} = the speed of the plane flying with the wind
{{{ p - w }}} = the speed of the plane flying against the wind
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Flying with the wind:
{{{ 645 = p + w }}}
{{{ 575 = p - w }}}
Add the equations
{{{ 1220 = 2p }}}
{{{ p = 610 }}} mi/hr
and
{{{ 645 = 610 + w }}}
{{{ w = 35 }}} mi/hr