Question 330147
     
In 4 Hours , Prof Ortiz would have travelled 4* 6 = 24 miles west
In 4 Hours ,Wilson would have travelled 4* 2.5 = 10 miles south
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The distance between them is the distance AB as depicted in the figure.
Note that they form 2 sides of a right angled triangle.
Using the Pyathogrean theorem,
{{{AB^2 = OA^2  + OB^2}}}
{{{AB^2 = 24^2 + 10^2}}}
{{{AB^2 = 576 + 100}}}
{{{AB^2 = 676}}}
{{{AB = sqrt(676)}}}
{{{AB= 26}}}