If electricity expenses rise from $4,000 to $4,400, what is the percentage increase?

If electricity expenses rise from $4,000 to $4,400, what is the percentage increase?

• A. 10%
• B. 9%
• C. 11%
• D. 12%

Answer: (A)

Think of percentage change as how much the amount grew relative to where it started. The increase is 4,400 minus 4,000, which equals 400. To turn that into a percent of the original 4,000, divide 400 by 4,000 and multiply by 100: (400 ÷ 4,000) × 100 = 0.10 × 100 = 10%. So the percentage increase is 10%. For context, 9% of 4,000 is 360, 11% is 440, and 12% is 480, which don’t match the actual increase.

Think of percentage change as how much the amount grew relative to where it started. The increase is 4,400 minus 4,000, which equals 400. To turn that into a percent of the original 4,000, divide 400 by 4,000 and multiply by 100: (400 ÷ 4,000) × 100 = 0.10 × 100 = 10%. So the percentage increase is 10%. For context, 9% of 4,000 is 360, 11% is 440, and 12% is 480, which don’t match the actual increase.