Answer: 38.7
Explanation: calculating percentages involve representing those percentages as fractions with denominator being a hundred or aa decimals. 215% represented as fraction becomes 215/100. As decimal it becomes 2.15. The operand "of" is in its basic form, multiplication. 215/100 [2.15 of 18] of 18 becomes 215/100 x 18 [2.15 x 18] which on working out gives you 38. 7 as the correct answer.