Question 1173836
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<pre>

x = rate of the prop plane;

4x = rate of the jet.


The time equation is


    {{{1600/(4x)}}} + {{{300/x}}} = 10  hours.


Simplify

    {{{400/x}}} + {{{300/x}}} = 10

    {{{700/x}}} = 10


       x   = {{{700/10}}} = 70 miles per hour  is the rate of the prop plane.

Hence, the rate of the jet is  4*70 = 280 mph.


<U>CHECK</U>.  {{{1600/280}}} + {{{300/70}}} = {{{40/7}}} + {{{30/7}}} = {{{70/7}}} = 10 hours.   ! Correct !
</pre>

Solved.