*Nice thinking* is the title of my new book (published on September 5) and it is also my advice for today’s puzzles.

**1. Hello ducklings**

There are two ducks in front of two ducks, two ducks behind two ducks and two ducks in between. What is the minimum number of ducks?

**2. Concentric puzzle**

Imagine I’m walking around a circle whose center is Big Ben. For the purposes of this question, assume I can walk on water.

When the radius is 1 km, I will walk approximately 6.28 km

When the radius is 100 km, I will walk approximately 628 km

When the radius is 10,000 km, I will walk about 62,800 km?

(The circumference of a circle is twice the radius times pi, which is 3.14 to two decimal places.)

**3. Hanging from a rope**

A bottle of water hangs from the ceiling by a rope. A handle hangs from the bottle by a piece of the same type of rope, as shown below.