Decrease = New number - Original Number
% Decrease =

× 100
Decrease = 9 - 12 = -3
% Decrease =

= -0.25 × 100 = -25
Your answer =
-25
The formula for this is

. Filling in accordingly,

. This simplifies to

and 36=6x. Therefore, x = 6 so the bases are 6 and 12.
Hello,
Let's assume t the time for counting one step
V the girl velocity in t
v the escalator velocity in t
d the length to go upstairs
going up: V*60+v*60=d
walking down: V*90-v*90=d
so
V+v=d/60
V-v=d/90
2V=d*5/180
V=d*5/360
V=d/72
V*72=d The girl must count to 72 steps.(here v=0)
Answer: 1) $54.74
2) $12.80
Step-by-step explanation: