Question

A woman can bicycle 66 miles in the same time as it takes her to walk 12 miles. She can ride 9 mph faster than she can walk. How fast can she walk?

Answer 1

is der choices?

Answer 2

No

Answer 3

k

Answer 4

in general:

distance = rate*time

so if you divide both sides by rate, you get

time = distance/rate

Answer 5

now, let's let

b = her bicycling speed
and w = her walking speed

for bicycling, the time equation becomes

time = 66/b
and for walking:

time = 12/w

since the time for both is equal, we can set both equations equal to each other to get

66/b = 12/w

Answer 6

finally:

"She can ride 9 mph faster than she can walk"

so b = w + 9

if we plug this into the equation from the previous step:

66/b = 12/w

becomes

66/(w+9) = 12/w

can you try solving this now? you'll need to start by cross-multiplying