Cost for 4 hours = $(3*4 +5) = $17suiyuan wrote:...1) Kenneth wants to rent a bicycle from Jim’s Bicycle Kiosk. The cost (C) of renting a bicycle for d hours is given by C = $(3d + 5). Find the cost of renting the bicycle if Kenneth wants to cycle for 4 hours. (2 marks)

BBBAA---suiyuan wrote:...

2) After 20 minutes in a cross-country race, Alan has run 5/8 of the route while Bernard has covered only 3/8 of the distance. Both run at a uniform average speed each and Bernard runs 60m/min slower than Alan.

(a) Find the total distance of the race.

(b) If Bernard wants to finish at the same time as Alan, by how much should he increase his average speed for the remainder of the race? Express the answer in m/min

(5 marks)

Let d be the total distance.

Distance travelled by being 60m/min faster after 20min

= (5/8 - 3/8 ) d = 2/8 * d

So 2/8 * d = 20x60 = 1200

=> d = 1200 * 8/2 = 4800

Edit 26 Sep 2008: See lantian's post further down in this thread.