<PRE><B>Question 943271</B>
Distance one way =D
D/22+D/10=4 find common denominator
D/22(5/5)+D/10(11/11)=4 hrs
5D/110+11D/110=4 hrs
16D/110=4 hrs multiply each side by 110
16D=440 Divide each side by 16
D=27.5 mi ANSWER The island is 27.5 mi from the harbor
CHECK 
round trip=time outbound(22 mph)+time inbound(10 mph)
4 hrs=27.5mi/22mph+ 27.5mi/10mph
4 hrs=1.25 hrs+2.75 hrs
4 hrs=4 hrs</PRE>