document.write( "Question 161535: togo flew his ultralight plane to a landing field 30 mi away. With the wind, the flight took 3/5h. Returning against the wind, the flight took 5/6h. Find the rate of the plane in still air and the rate of the wind. \n" ); document.write( "
Algebra.Com's Answer #119007 by gonzo(654)![]() ![]() ![]() You can put this solution on YOUR website! togo flies 30 miles in 3/5 of an hour with the wind. \n" ); document.write( "togo flies 30 miles in 5/6 of an hour against the wind. \n" ); document.write( "----- \n" ); document.write( "his rate of speed with the wind was 30 / (3/5) = 30*5/3 = 150/3 = 50 mph. \n" ); document.write( "his rate of speed against the wind was 30 / (5/6) = 30*6/5 = 6*6 = 36 mph. \n" ); document.write( "----- \n" ); document.write( "3/5 of an hour times 50 mph = 30 miles. \n" ); document.write( "5/6 of an hour times 36 mph = 30 miles. \n" ); document.write( "----- \n" ); document.write( "mph looks good. \n" ); document.write( "----- \n" ); document.write( "going he was with the wind. \n" ); document.write( "his rate of speed then was the airplane speed plus the wind speed. \n" ); document.write( "coming back he was against the wind. \n" ); document.write( "his rate of speed then was the airplane speed minus the wind speed. \n" ); document.write( "----- \n" ); document.write( "50 mph = A + W \n" ); document.write( "36 mph = A - W \n" ); document.write( "----- \n" ); document.write( "looks like A + W - (A - W) should equal 50 - 36. \n" ); document.write( "removing parentheses, equation becomes \n" ); document.write( "A + W - A + W = 14. \n" ); document.write( "combining like terms, the equation becomes \n" ); document.write( "2*W = 14. \n" ); document.write( "dividing both sides by 2, equation becomes \n" ); document.write( "W = 7. \n" ); document.write( "if W = 7, then A can be found as follows: \n" ); document.write( "50 = A + 7 \n" ); document.write( "A = 43. \n" ); document.write( "likewise, \n" ); document.write( "36 = A - 7 \n" ); document.write( "A = 43. \n" ); document.write( "since the airplane speed is the same, it looks like the answer is good. \n" ); document.write( "solving in the original equations, we get \n" ); document.write( "3/5 * (43 + 7) = 30 \n" ); document.write( "3/5 * 50- = 30 \n" ); document.write( "30 = 30 \n" ); document.write( "good. \n" ); document.write( "----- \n" ); document.write( "5/6 * (43 - 7) = 30 \n" ); document.write( "5/6 * 36 = 30 \n" ); document.write( "30 = 30 \n" ); document.write( "good. \n" ); document.write( "----- \n" ); document.write( "answer is W = 7 and A = 43. \n" ); document.write( " |