A possible answer is:
"I have 0.5 of a pizza left. There are 3 people eating it for lunch. What part of the whole pizza is each person eating for lunch?"
Explanation:
Rational numbers are any numbers that can be written as fractions. Whole numbers can be written as fractions, too, by writing them over a denominator of 1. This means we want to create a problem involving division of fractions and/or whole numbers.
