A student divided a number by 7/2 instead of 2/7. Calculate the percentage error.
A88.25%
B91.8%
C81.9%
D92%
Answer:
B. 91.8%
Read Explanation:
Let the number be 'X'.
The student divides the number by 7/2. Thus, error value = X//(7/2) = 2X/7
But it should be divided by 2/7. Thus, true value = X/(2/7) = 7X/2
Difference in the two values = (7X/2) - (2X/7) = 45X/14
Required % error = (difference in two values/true value) × 100
= [(45x/14)/(7x/2)] × 100 = 91.8%
