Question

There are 40 papers of students of a class to be checked by two teachers, Mr. Ashok checks five papers in an hour and Mrs Meena can check 4 papers in an hour. If mr. Ashok can spend three hours in checking the papers and mrs. Meena works for two hours. Find the percentage of papers that will be checked in all?

Answer 1

Hint: In this question, apply the unitary method to find the total number of papers checked by Mr. Ashok in three hours, and then the total number of papers checked by Mrs Meena in two hours. Then find the total paper checked all together by both the teachers. Now in order to find the percentage we use the formula \[\left( \dfrac{total\,\,checked}{40}\times 100\, \right)%\].

Complete step-by-step answer:
In the question, we are given that there are 40 papers of students of a class to be checked by two teachers, Mr. Ashok checks five papers in an hour and Mrs Meena can check 4 papers in an hour. If Mr. Ashok can spend three hours in checking the papers and Mrs. Meena works for two hours, then we have to find the percentage of papers that will be checked in all.
So now, we will first find the total papers checked by Mr. Ashok in three hours using the unitary method. Now, in one-hour Mr. Ashok can check 5 papers, so in three hours he can check
\[5\times 3=15\]papers. Similarly, we will next find the total papers checked by Mrs Meena in two hours using the unitary method. Now, in one-hour Mrs Meena can check 4 papers, so in two hours she can check \[4\times 2=8\] papers. Now, the total papers checked altogether by both the teachers are: \[15+8=23\] papers.
Now, there are altogether 40 papers to be checked, so the percentage of already checked will be found by the formula \[\left( \dfrac{total\,\,checked}{Total\,papers}\times 100\, \right)%\]. So, this gives the required percentage as;
\[\begin{align}
  & \Rightarrow \left( \dfrac{total\,\,checked}{Total\,papers}\times 100\, \right)\% \\
 & \Rightarrow \left( \dfrac{23}{40}\times 100\, \right)\% \\
 & \Rightarrow \left( 57.5 \right)\% \\
\end{align}\]
Hence, the percentage of papers that is checked in all is \[\left( 57.5 \right)\%\].

Note: We have to be careful while doing the calculation, especially when we are finding the percentage. To find the percentage don’t forget to multiply by 100. The percentage symbol is also required to be given at the end in the answer.