Answer:
Ginny will cast 2525 spells
Step-by-step explanation:
The ratio of spells Luna casts to spells Ginny casts is:
Luna :4
Ginny :5
4 spells of Luna is equivalent to 5 spells of Ginny
1 spell of Luna is equivalent to 5/4 spells of Ginny
Luna casts 2020 spells
It means Ginny will cast spells
i.e. Ginny will cast 2525 spells