Answer:
166.67 ohm
Step-by-step explanation:
Complete statement of the question is :
You have a collection of six 1.0 kO resistors. What is the smallest resistance you can make by combining them?
When we connect resistors in parallel, the combination resistance is always smaller than the smallest resistance value we combine.
Parallel Combination of resistances is given as

where
= Equivalent resistance
and
are resistances in parallel.
So for the above question, we have

So parallel combination is given as

So the smallest resistance is 166.67 ohm