Wei drives 24 miles to school on both rural and city roads. He candrive 45 miles per hours on rural roads and 354 miles per hour on city streets. It takes him about 40 min. to comute to school. how much time does he drive on rural routes? how much time does he drive on city streets?
2006-11-20 03:18:38 · 2 answers · asked by Erica C 1 in Science & Mathematics ➔ Geography
If he is driving 354 mph on city streets, he would be spending less than a minute on them.
2006-11-20 03:29:35 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Let's suppose you meant 45 rural, 35 city, and define r as minutes driving rural, c as minutes driving city. Then 24=(45*r+35*c)/60, and r+c=40. Substituting, 60*24=45*r+35*(40-r), or 1440-1400=10*r. Then r=4 and c=36. Answer is 36 minutes city driving.
Checking, (4*45+36*35)/60=24.
2006-11-20 11:50:33 · answer #2 · answered by kirchwey 7 · 0⤊ 0⤋