Janae was vacuuming the narrow hallway in her house. She went 5 feet forwards in the first 4 seconds, then went 3 feet backwards in the next 4 seconds. She continued to do this, forwards 5 feet in 4 seconds and backwards 3 feet in 4 seconds. If she continues in this way, how many seconds will it take her to reach the end of her hallway, which is 15 feet long? 1.

Question

Mathematics

Lacey

25 September, 06:35

Janae was vacuuming the narrow hallway in her house. She went 5 feet forwards in the first 4 seconds, then went 3 feet backwards in the next 4 seconds. She continued to do this, forwards 5 feet in 4 seconds and backwards 3 feet in 4 seconds. If she continues in this way, how many seconds will it take her to reach the end of her hallway, which is 15 feet long? 1.

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Answers (1)

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Mariana Benitez · Answer 1

60 seconds

Step-by-step explanation:

Hi!

After she goes forward 5 feet (4 seconds), and the backwards 3 feet (another 4 seconds), the total distance forward she travelled is 2 feet. Then, she moved forward 2 feet in 8 seconds.

Then, as this is repeated, she moves forward 2 feet every 8 seconds. After 7 repetitions she travelled 14 feet, and 56 seconds elapsed. Then she goes forward 5 feet in 4 seconds, and she finaly reaches the end of the hallway

(14 + 5 > 15)

So, in 60 seconds she reached the end of the hallway.