## The number of flights leaving a certain airport doubles during every one-hour period between its 9 A.M. opening and noon

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### The number of flights leaving a certain airport doubles during every one-hour period between its 9 A.M. opening and noon

by Gmat_mission » Sun Jun 14, 2020 2:40 pm

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## Global Stats

The number of flights leaving a certain airport doubles during every one-hour period between its 9 A.M. opening and noon; after noon, the number of flights leaving from the airport doubles during every two-hour period. If 4 flights left from the airport between 9 and 10 a.m., how many flights left the airport between 2 and 4 P.M.?

(A) 32
(B) 48
(C) 64
(D) 128
(E) 256

[spoiler]OA=C[/spoiler]

Source: Princeton Review

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### Re: The number of flights leaving a certain airport doubles during every one-hour period between its 9 A.M. opening and

by [email protected] » Sat Jun 20, 2020 2:05 pm
Gmat_mission wrote:
Sun Jun 14, 2020 2:40 pm
The number of flights leaving a certain airport doubles during every one-hour period between its 9 A.M. opening and noon; after noon, the number of flights leaving from the airport doubles during every two-hour period. If 4 flights left from the airport between 9 and 10 a.m., how many flights left the airport between 2 and 4 P.M.?

(A) 32
(B) 48
(C) 64
(D) 128
(E) 256

[spoiler]OA=C[/spoiler]

Solution:

We can tabulate the number of planes every hour before noon and every two hours after noon:

Between 9 am and 10 am: 4

Between 10 am and 11 am: 8

Between 11 am and noon: 16

Between noon and 2 pm: 32

Between 2 pm and 4 pm: 64

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### Re: The number of flights leaving a certain airport doubles during every one-hour period between its 9 A.M. opening and

by ArmaniPhillips » Fri Feb 03, 2023 6:10 am
This is useful information

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