Question

A person walks up a stalled escalator in 90 seconds. When standing on the same escalator, now moving, he is carried up in 60 seconds. How much time would it take him to walk up the moving escalator ?

• A. 45 secs
• B. 75 secs
• C. 36 secs
• D. 30 secs

Answer 1

Answer: (C)

36 secs

Answer 2

t = $\frac { \text { distance } } { \mathrm { V } _ { \mathrm { man } } + \mathrm { V } _ { \mathrm { esc } . } }$ = $\frac{s}{\frac{s}{90} + \frac{s}{60}}$