Problem: Which Verdi opera is based on the play Le Roi S'amuse by Victor Hugo?
======
A: rigoletto

Problem: How many zeros are in a US billion?
======
A: nine

Problem: Mimi is the heroine of which opera?
======
A: la boheme

Problem: Which tube station locates and describes someone "eight stops short of Upminster"?
======
A:
barking