Question 508978
Let {{{p}}} = speed of the jet in calm air
Let {{{w}}} = speed of wind
given:
(1) {{{ p + w = 2520/4 }}}
(2) {{{ p - w = 1720/4 }}}
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(1) {{{ p + w = 630 }}}
(2) {{{ p - w = 430 }}}
Add the equations
{{{ 2p = 1060 }}}
{{{ p = 530 }}}
and, since
(2) {{{ p - w = 430 }}}
(2) {{{ 530 - w = 430 }}}
(2) {{{ w = 530 - 430 }}}
(2) {{{ w = 100 }}}
The speed of the jet in calm air is 530 mi/hr