# How many apples should you carry? [duplicate]

You are on your way to your friend's house. You decide to carry 2 apples to your friend. To get to their house, you must pass across 8 gates. At each gate, the keeper will take half the amount of apples you have and return one apple back. The question is, how many apples should you carry at the beginning?

• if there was a lateral thinking tag: start with zero apples, walk through the gate, throw your apple over the next gate, then you will have two apples! Commented Sep 10, 2018 at 19:48
• And that's why I didn't include it, cuz I know some people have an infinitely broad imagination! Commented Sep 10, 2018 at 19:53

You need

2 apples.

This is because

Each gatekeeper will take one apple (half of two) and return one to you, meaning you keep the same number of apples through each gate.

• Haha.. Just missed it! :) Commented Sep 10, 2018 at 15:49

I am not sure if it's this easy. But here's a try.

You need to carry only 2 Apples. At each gate, the keeper will take half the amount i.e. 1 apple and will return it. At the end, you are still left with 2 apples.

• Close one! I think I barely beat you in, but great answer nonetheless! :D Commented Sep 10, 2018 at 15:49
• That's correct, but @El-Guest answered first :) Commented Sep 10, 2018 at 15:49
• @El-Guest I guess yours is. Commented Sep 10, 2018 at 15:49
• Yeah, very close :) Commented Sep 10, 2018 at 15:51

Well,

Let’s work backwards: (2 apples - 1) * 2 = 2. Therefore, you only need to bring 2 apples.

Also,

You could only bring one apple, and walk through the gates and back. Then you should have around 1.8 apples. Then leave the .8 and repeat for infinite apples! :P

• Ah, I see now. I will change my answer Commented Sep 10, 2018 at 15:46
• Nice one (never thought of this tbh)! Commented Sep 10, 2018 at 15:53
• @Wais Kamal And neither did the gatekeepers, apparently! Commented Sep 10, 2018 at 15:54