Peter was 60 inches tall on his thirteenth birthday. By the time he turned 15, his height had increased 15%. How tall was Peter when he turned 15?
Find 15% of 60 inches and add it to 60 inches. Find 15% through multiplying 60 by the decimal equal of 15% (0.15); 60 × 0.15 = 9. Add 9 inches to 60 inches to get 69 inches.