Solution

\[ \begin{align*} \text{No. of papers Mr. Ashok can check in 1 hour} & = 5 \\ \text{No. of papers Mr. Ashok checks in 3 hours} & = 5 \times 3 \\ &= 15 \\ \\ \text{No. of papers Mrs. Meena can check in 1 hour} & = 4 \\ \text{No. of papers Mrs. Meena checks in 2 hours} & = 4 \times 2 \\ &= 8 \\ \\ \text{Total papers checked by both} & = 15 + 8\\ & = 23 \\ \\ \text{Total number of papers} & = 40 \\ \\ \text{Percentage of papers checked} & = \left(\frac{23}{\cancel{40}_2} \times \cancel{100}^5 \right)\% \\ \\ & = \left(\frac{23 \times 5}{2} \right)\% \\ \\ & = \left(\frac{115}{2} \right)\% \\ \\ & = 57.5\% \end{align*} \]

Answer Percentage of papers checked \( = \color{red} 57.5\% \)