8th Class Mathematics Comparing Quantities Question Bank Comparing Queantities

  • question_answer A student multiplied a number by 3/5 instead of 5/3. What is the percentage error in the calculation?

    A)  34%                

    B)  44%          

    C)  54%                            

    D)  64%

    Correct Answer: D

    Solution :

    (d): Let no be 'n' He gets \[\frac{3}{5}\]n instead of \[\frac{5}{3}\]n \[\therefore Error%\text{ }age=\frac{absolute\text{ }error}{required\text{ }no}\] \[=\frac{\frac{5}{3}n-\frac{3}{5}n}{\frac{5}{3}n}\] \[=\frac{\frac{(25-9)n}{15}}{\frac{5n}{3}}\]     \[=\frac{16n}{15}\times \frac{3}{5}=\frac{48}{75}\] \[=\frac{48}{75}\times 100%\] \[=\frac{48\times 4}{3}%=64%\]   


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