help please

Hey!

So let's start off by doing some conversions.

(Whisper) there's $5280$ feet in a mile (Whisper)

Ok, since we already know that $1$ mi = $5280$ ft,

We can set up a ratio to figure out that $15.5$ mi = $(15.5 \times 5280$) = $81,840$ ft.

Now, that's not our answer just yet.

We have to do the second conversion.

Because we know how time works, there's $60$ minutes in an hour.

We need the speed in $\frac{\text{ft}}{\text{min}}$, so we have $\frac{81840}{60}$ = $\boxed{1,364 \frac{\text{ft}}{\text{min}}}$

Via dimensional analysis.....note how things cancel out and you are left with  f / m

15.5  mile / hr    x    1 hr / 60 m      x   5280 ft / mile    =  1364 f / min

60 mph  = 88 ft/s

So

x / 15.5  =  88/ 60        cross-multiply

60x  = 15.5 * 88

x  =   15.5  * 88  / 60   = 341 /15  ft /s

So

341 / 15  *  60  ≈  1364  ft / min