Day 25 Week 4 Day 4: The Rule of 72 Works Against You Too Compounding Credit card debt at 24% interest doubles in just 3 years. The Rule of 72 is a weapon that cuts both ways.... Credit card debt at 24% interest doubles in just 3 years. The Rule of 72 is a weapon that cuts both ways. Lesson Locked This Lesson Is For Paid Subscribers Subscribe to access the full lesson, commentary, and your day-by-day course progression. Start Learning - $9.99/month View Full Syllabus ← Previous Lesson Back to Browse Next Lesson →