Directions: Read the following information to answer the question.
Directions: Read the following information to answer the question.
A man can walk up a moving ‘up’ escalator in1/2 minutes. He can walk down this moving ‘up’ escalator in 1.5 minutes. His walking pace is the same up stairs as it is down stairs.
In 1.5 minutes the man can walk down 1 moving escalator or up 3. In 3
minutes walking, half the time up and half the time down, he can walk 4
escalator lengths. This is his walking pace – 4 escalator lengths in 3 minutes
– for the effect of the moving escalator is canceled. He can therefore climb
(or descend) the still escalator in 1/4 of 3 minutes, or 45 seconds. In the 1.5
minutes required to walk down the moving “up” escalator he walks the
equivalent of 2 still escalators. Therefore the escalator must have moved
up once in that lime and its speed is 1 length In 1.5 minutes.
Aliter : If x = number of steps, e = speed of escalator and m = speed of man,
we get e + m = x/30; –e + m = x/90. On adding these equations, we get
m = x/45 and e comes to x/90. We can now solve for required values.
Using the Venn diagram
People who are O-ve = 100 – n (A∪B∩Rh)
=100 – [40 + 18 + 82 – 5 – 31 – 11 + 4]
=100 – 97
= 3
