An airplane flew at an average rate of 600 miles per hour from tokyo to seattle. because of a strong headwind, the average rate of the return trip was only 480 mph. the round trip took 18 hours.

Hello,

I suppose you want to know the distance d between Tokyo and Seattle.

Let's t1 the time going and t2 time return

d=600*t1

t1+t2=18

600*t1=480*t2 = = >t2=60/48 * t1

==> t1+60/48*t1=18

==>108*t1=18*48

==>t1=8 (hours), t2=18-8=10 (hours)

d=600*8=4800 mi.