Christmas riddle

Problem Solving is a key part of being a Newton consultant. That's why we created this Christmas riddle for you to solve!

Submit your answer below (and follow us on Instagram @newtoneurope) to be in with a chance of winning a £100 Etsy gift card or one of five £20 Waterstones gift cards.

Alternatively, we can donate the equivalent amount to a charity of your choice.

You’ve decorated your tree with 3 sets of old lights.

You’re outside the room with 3 switches, each controlling one set of lights.

You can only enter the room once and can't see the lights from outside the room.

How can you determine which switch controls each set of lights?

You’ve decorated your tree with 3 sets of old lights.

You’re outside the room with 3 switches, each controlling one set of lights.

You can only enter the room once and can't see the lights from outside the room.

How can you determine which switch controls each set of lights?