Question 1124065
Let {{{ s }}} = the jet’s speed going from a to b
{{{ 1.2s }}} = the jet’s speed going from b to a
Let {{{ t }}} = jet’s time going from a to b
{{{ 9 + 1/6 - t }}} = jet’s time from b to a
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Equation for a to b:
(1) {{{ 2500 = s*t }}}
Equation for b to a:
(2) {{{ 2500 = 1.2s*( 9 + 1/6 - t ) }}}
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(1) {{{ t = 2500/s }}}
Plug this result into (2)
(2) {{{ 2500 = 1.2s*( 9 + 1/6 - 2500/s ) }}}
(2) {{{ 2500 = 10.8s + .2s - 3000 }}}
(2) {{{ 11s = 5500 }}}
(2) {{{ s = 500 }}}
The speed from a to b was 500 mi/hr
———————-
Check:
(1) {{{ t = 2500/500 }}}
(1) {{{ t = 5 }}} hrs
And
(2) {{{ 2500 = 1.2s*( 9 + 1/6 - 5 ) }}}
(2) {{{ 2500 = 1.2*s*( 4 + 1/6 ) }}}
(2) {{{ 2500 = s*( 4.8 + .2 ) }}}
(2) {{{ s = 2500/5 }}}
(2) {{{ s = 500 }}}
OK