Question 19

An escalator moves up at a constant rate. John walks up the escalator at the rate of one step per second and reaches the top in twenty seconds. The next day John's rate was two steps per second, and he reached the top in sixteen seconds. The number of steps in the escalator is

Correct Answer: 80

Solution

Let the escalator move at $$r$$ steps per second and let the total number of steps be $$N$$. The two journeys give $$N=20(r+1)$$ and $$N=16(r+2)$$. Equating them gives $$20r+20=16r+32$$, so $$r=3$$ and therefore $$N=20(4)=80$$.

Get AI Help

Other Cracku’s Useful Resources:

JEE Questions JEE Question Bank JEE Mains Previous Papers JEE Advanced Previous Papers JEE Study Material PDF JEE Mains Mock Test JEE Advanced Mock Test JEE Daily Target

Free JEE Questions

JEE Physics Questions JEE Maths Questions JEE Chemistry Questions

An escalator moves up at a constant rate. John walks up the escalator at the rate of one step per second and reaches the top in twenty seconds. The next day John's rate was two steps per second, and he reached the top in sixteen seconds. The number of steps in the escalator is

Solution

Get AI Help

Other Cracku’s Useful Resources:

Free JEE Questions

50,000+ JEE Students Trusted Our Score Calculator

Download resources