Km/h question?

Question

The Nature Club members are on a hike and walk at an average speed of 5km/h. The lunch committee follows an hour later walking at 9km/h. How far from camp will the luch committee catch up to the other club members.

Answer 1

the distance for normal members
dist = 5*t;

the distance for lunch members
dist = 9*(t-1)

t is in hours

equal the dist and solve for t gives
5t = 9t - 9
or 4t=9 or t = 9/4 hours = 2 1/9 hour

so after a little bit more than 2 hour they are catched up.

the distance they walked then is dist = 5*t = 5*9/4 = 45/4
(or) dist = 9t - 9 = 9* 9/4 - 9 = 45/4 kilomerter

Answer 2

When the committee start, the walkers are 5 km ahead of them. They are catching them up at the rate of (9 - 5) = 4 km/h, so it will take them an hour and a quarter.

Distance covered: (1) walkers 2 1/4 hours at 5 km/h = 11 1/4 km, (2) committee 1 1/4 hours at 9 km/h = 11 1/4 km, same distance.

So the distance is 11 1/4 km.