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: 72+6n
Step-by-step explanation: Subtract the values 81 and -9
72+10n-4n=
72+6n
Answer:
angle a is 73 and angle c is 180-(73+73)=34
(x^1/8 y^1/4 z^1/2)^8
(8 √x 4 √y √z^8)
(8 √x 8 √y^2 8 √z^4)^8
8 √xy^2z^4^8
Solution: xy^2 z^4
