Serviceline Industrial Sensors
Serviceline Explosion Protection

Did You Figure it Out? Get the Answer to the Riddle from E-News Issue No. 2, March 2019


The Joys of Hiking

How heavy are the backpacks?

The annual hiking trip is coming up and friends Max and Paul are complaining about their heavy backpacks filled with provisions. Paul is bigger than Max, so Max asks if Paul will carry his 5 kg food bag. Paul, however, does not think that he should carry twice as much as Max simply because of the difference in their sizes. In fact, Paul has a 5 kg food bag that he wants Max to carry so their backpacks are the same weight.

How heavy are Max's and Paul's backpacks?


Let's say Max’s backpack weighs x and Paul’s weighs y. The following equations result:

I. 2 ( x – 5 ) = y + 5, or                     
   2x – 10 = y + 5

II. x + 5 = y – 5

By subtracting the 2nd equation from the 1st equation, you get:

x – 15 = 10, so

x = 25 kg and y = 35 kg

Thus, Max's backpack weighs 25 kg and Paul's weighs 35 kg.


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

amplify–The Pepperl+Fuchs Magazine

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