Suppose half of the passengers on a bus exit at each stop and no addit

Question

Suppose half of the passengers on a bus exit at each stop and no additional passenger boards in the bus. If on the fourth stop, the next to the last person exits the bus, how many people were on the bus?

A) 64
B) 32
C) 40
D) 20
E) 16

Show Answer

Official Answer

E

A) 64 
B) 32 
C) 40 
D) 20 
E) 16

abhi398 · Answer

if half person exits as each stop then :

let x be the total passengers in the bus

1st stop -->x/2 get down
2nd stop -->x/4 get down
3rd stop -->x/8 get down
4th stop -->x/16 get down

if next to the last person exits the stop means:

x/16(no of passengers that get down on the fourth stop)=1
hence 
-->x=16.

answer E

KarishmaB · Answer

Many questions can be solved without involving much Math. Start from what is given to you. You know that on the fourth stop, 1 person exited and 1 person was left on the bus. This means that before the fourth stop, there were 2 people on the bus. On the third stop, two people must have exited leaving 2 on the bus. On the second stop, 4 people must have exited. On the first stop, 8 people must have exited. Therefore, before the first stop, there must have been 16 people on the bus.

jitbec · Answer

Also we can also do it quickly by elimination. cleary the answer has to be power of 2. So C) and d) are ruled out. Then lets try with 64. it will come 32--16--8. Clearly too big. So lets go to 16. 8-4-2.
Gotcha :-D

.

.

kkalyan · Answer

hi 
 can u plz tell how"the next to the last person exits the bus" =1 .
Wat does it mean actually.

fluke · Answer

2nd last person exits. 
Or
1 out of the last 2 persons exits.

After all, 1 is half of 2.

bumpbot · Answer

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Suppose half of the passengers on a bus exit at each stop and no addit

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Suppose half of the passengers on a bus exit at each stop and no addit

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