Let the time for which man travels on foot =x h Then, the time for which man travels on bicycle =(7−x)h Now, according to the question, 8×x+16(7−x)=80 [∵ Distance = Speed × Time ] ⇒‌‌8x+112−16x=80 ⇒‌‌−8x=−112+80⇒8x=32 ⇒‌‌x=‌