More functions from descriptions: A tourist walks n km at...

[soulofeternity]

Okay, I am terrible at these. I really hate doing them and I don't see even the simplest of things when I am working one of these because I get so confused. So if I sound really stupid, that's why.

Question-A tourist walks n km at 4km/h and then travels 2n at 36km/h by bus. Express the total time t (in hours) as a function of n.

Answer- 11n/36

I don't understand how they got 11n or why they are dividing by 36. . .

 

[galactus]

Hello soul:

Here's how they done that.

Distance = (rate)*(time)

Therefore, time=distance/rate


You're given rates and the distances as n and 2n.

\(\displaystyle \L\\time=\frac{\overbrace{n}^{\text{distance}}}{\underbrace{4}_{\text{rate}}}+\frac{\overbrace{2n}^{\text{distance}}}{\underbrace{36}_{\text{rate}}}\)

I'll let you simplify to the required answer.

 

[soulofeternity]

Thank you for your help! ^.^