Difference between revisions of "1990 AJHSME Problems/Problem 19"

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(Solution)
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==Solution==
 
==Solution==
  
p is a person seated, o is an empty seat
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<math>p</math> is a person seated, <math>o</math> is an empty seat
  
 
The pattern of seating that results in the fewest occupied seats is opoopoopoo...po
 
The pattern of seating that results in the fewest occupied seats is opoopoopoo...po

Revision as of 07:19, 15 November 2019

Problem

There are $120$ seats in a row. What is the fewest number of seats that must be occupied so the next person to be seated must sit next to someone?

$\text{(A)}\ 30 \qquad \text{(B)}\ 40 \qquad \text{(C)}\ 41 \qquad \text{(D)}\ 60 \qquad \text{(E)}\ 119$

Solution

$p$ is a person seated, $o$ is an empty seat

The pattern of seating that results in the fewest occupied seats is opoopoopoo...po we can group the seats in 3s opo opo opo ...opo

there are a total of $\boxed{B}$ groups

See Also

1990 AJHSME (ProblemsAnswer KeyResources)
Preceded by
Problem 18
Followed by
Problem 20
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AJHSME/AMC 8 Problems and Solutions