Jack enters a lift on the 25th floor, which is going up @ 56 floors/min speed. At the same time Jill

M4maths Previous Puzzles

04 Jan 2019 Lift

Jack enters a lift on the 25th floor, which is going up @ 56 floors/min speed. At the same time Jill enters another lift on the 70th floor which is going down @ 64 floors/min speed. At what floor will

they be together?

OPtion

1) 41
2) 42
3) 43
4) 44
5) 45
6) 39
7) 47
8) 46
9) 48
10) None of these

Solution

Relative Speed = 56+64 = 120 floors/min
Relative Distance = 70 - 25 = 45 floors

Time to cover 45 floors = 45*60/120 = 22.5 seconds

Floors travelled by Jack in 22.5 seconds = (56/60)*22.5 = 21
Floors on which they will meet = 25 + 21 = 46th
Option 8)

Correct Option: 8 Best Solution (6)

G.S.Kantharao   5 years AGO

Let x is the floor they meet
(70-x)/64=(x-25)/56
(70-x)56=(x-25)64
3920-56x=64x-1600
120x=5520=>x=5520/120=46
Right option is 8👈

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SAYAN CHATTERJEE   5 years AGO

25+56x= 70-64x
x= 0.375
So, floor is 25+56*0.375= 46.
Option 8.

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RISHIKA AGARWAL   5 years AGO

They will meet after t time so Time is constt here.
D/S=constt
Distance ratio = Speed Ratio= 56/64=7/8
Total floor between 25th and 70th = 70-25= 45 (This is 15 *3)
So Jack will travel 7*3=21 floors from 25th and Jill will travel 8*3=24 floors from 70th to meet Jack.
So they will meet at 25+21 or 70-24 =46th Floor.

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Devendra Marghade   5 years AGO

Relative speed (in opposite direction)=56+64=120 floors/min.
Difference between them=70-25=45 floors.
So time taken to meet = 45/120 = 3/8 min.
Floors covered up by Jack in 3/8 min=56*3/8=21
Hence they meet at 25+21=46th floor.
Option 8)

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balaji   5 years AGO

after 22.5 minute they will together

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Kariamal   5 years AGO

Relative speed=56+64=120
Relative distance=70-25=45
So, 45/120*60=22.5
56/60*22.5=21
Floors on which they will meet=21+25=46

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