Question

9. Lisa can ride her bike to work in 2/3 of an hour. When she drives to work it takes 1/3 of an hour. If she drives 12 miles per hour faster than she rides her bike, how fast does she ride her bike?
12 mph
6 mph
15 mph
18 mph

Answer 1

let
\[v_c=v+12\]
\[v_b=v\]

Answer 2

let v be her "normal" velocity
and s be the distance to work

s = v * (2/3)

s = (v+12) * (1/3)

divide the equations and get

(v+12) = 2v
v = 12

Answer 3

if

\[V=\frac{d}{t}\]
\[v*t=d\]

Answer 4

thanksssss

Answer 5

since distances are the same

\[v*\frac{2}{3}=(v+12)\frac{1}{3}\]

\[\frac{2}{3}v=\frac{1}{3}v+4\]

\[\frac{1}{3}v=4\]

\[v=12\]