I am having a difficult time with this algebra stuff, especially with rate-time-disance problems. And I was wondering if any of you could help me with these problems. But best of all help me understand this whole rate-time-disance thing. So here are the problems.

Kwan hiked up a hill at 4km/h and back down at 6 km/h. His total hiking time was 3 h. How long did the trip up the hill take him?


A bus traveled 387 km in 5 h. One hour of the trip was in city traffic. The bus city speed was just half of its speed on open highway. The rest of the trip was on open highway. Find the bus's city speed.

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Kwan hiked up a hill at 4km/h and back down at 6 km/h. His total hiking time was 3 h. How long did the trip up the hill take him?

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Since d=rt, we can solve for t=d/r. It's the same distance up hill as back down.

So uphill his time is d/4.

Downhill time is d/6



Solve for d and plug in to find your respective times.

Quote:

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A bus traveled 387 km in 5 h. One hour of the trip was in city traffic. The bus city speed was just half of its speed on open highway. The rest of the trip was on open highway. Find the bus's city speed.

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The bus travels a distance of in the city and a distance of 4r on the highway.

So,

Solve for r.