Serviceline
Serviceline Industrial Sensors
Serviceline Explosion Protection

Did You Figure it Out? Get the Answer to the Riddle from E-News Issue No. 5, November 2018

2018-11-07

How Long Has Peter Lived in the Village?

house in village
The traffic in the village increased 15% each year.

A few years ago, Peter moved from the city to a small, quiet village in the countryside. In the beginning, a car only drove past his house every eighth minute, Little by little, the small village grew, and the traffic increased 15% each year. Today, Peter looks back at the time that has passed and says: "The quiet years are long gone. Now, twice as many cars drive past my house as in the beginning."

How long has Peter been living in the village?

 


Solution

Based on percentages, the following calculation results:

  • In the first year 100 % cars drove past Peter’s house
  • In the second year 115 % (100 * 1.15)
  • In the third year 132.25 % (115 * 1.15)
  • In the fourth year 152.09 % (132.25 * 1.15)
  • In the fifth year 174.90 % (152.09 * 1.15)
  • In the sixth year 201.13 % (174.90 * 1.15)

Since twice as many cars—meaning 200 %—now pass by Peter's house, according to this calculation, he has already lived in the village for six years.


e-news

Subscribe to our newsletter for news and interesting information from all around the world of automation.

Subscribe

Read the current issue of e-news:

amplify–The Pepperl+Fuchs Magazine

Discover our online magazine! Exciting success stories, application reports, interviews, and regional news are awaiting you.