question_answer

A boy found the answer for the question "Subtract the sum of 1/4 and 1/5 from unity and express the answer in decimals" as 0.45. The percentage of error in his answer was [SSC CGL Tier II, 2017]

A)        (100/11)%

B) 50%

C) 10%

D) (200/11)%

Correct Answer: D

Solution :

[d] According to the question, Answer he found \[=0.45=\frac{45}{100}=\frac{9}{20}\] \[\therefore \] Required error percentage \[=\frac{\frac{11}{20}-\frac{9}{20}}{\frac{11}{20}}\times 100=\frac{\frac{2}{20}}{\frac{11}{20}}\times 100\] \[=\frac{2}{11}\times 100=\frac{200}{11}%\]