A student was supposed to multiply a number by 19/18 but instead multiplied it by 9/8. Find the percentage error in the student's calculation.
Show answer & explanation
Correct answer: D
Explanation
Given:
Correct Product = 19/18
Incorrect Product = 9/8
Percentage Error = [(Incorrect − Correct) / Correct] × 100
= [(9/8 − 19/18) / (19/18)] × 100
9/8 = 81/72, 19/18 = 76/72
= (5/72) ÷ (19/18) × 100
= (5/72 × 18/19) × 100
= (90 / 1368) × 100
= (15 / 228) × 100
= (5 / 76) × 100
= 6.58%