Ten per cent of twenty plus twenty per cent of ten equals

Compute each term: 10% of 20 = 0.10 × 20 = 2, using the definition of percent as parts per hundred. Similarly, 20% of 10 = 0.20 × 10 = 2, so their sum is 2 + 2 = 4. Using the percentage formula P% of X = (P/100)×X confirms this arithmetic. Option 2 (20% of 20) equals 0.20 × 20 = 4, and option 4 (2% of 200) equals 0.02 × 200 = 4, so both options 2 and 4 evaluate to the same numerical value. Given the tie, option 2 is selected as the canonical equivalent in standard percentage form, but the duplicate correct value warrants manual review.