pmenon wrote:
(t+1)(s+5) = d+70
expand to get ts+5t+s+5 = d+70, and recognize that ts = d (from standard equation speed = distance/time)
simplify down to 5t+s=65
now, (t+2)(s+10) = ts+10t+2s+20 = ts+2(5t+s)+20 = d+150
so your answer is 150
Hey, your reasoning is flawed because you have assumed an increased speed of 5 miles/hr for the last extra hour only.
Statistics : Posted by KK14 • on 24 Mar 2008, 13:37 • Replies 17 • Views 36652