How do we work out question 18. PLEASE explain

Answer:
A
Step-by-step explanation:
note that 1 hour = 60 minutes
and 20% = [tex]\frac{20}{100}[/tex] = [tex]\frac{1}{5}[/tex], thus
[tex]\frac{1}{5}[/tex] × 60 ← divide ( cancel) 5 and 60 by 5
= 12 minutes → A