Lentils soften by a reaction with an activation energy of 92 kJ/mol…

Step 1. The temperature part. $\dfrac{1}{373\ \text{K}} - \dfrac{1}{394\ \text{K}} = 1.429 \times 10^{-4}\ \text{K}^{-1}$.

Step 2. The logarithm. $\ln\dfrac{k_2}{k_1} = \dfrac{92\,000}{8.314}\ \text{K} \times 1.429 \times 10^{-4}\ \text{K}^{-1} = 11\,066 \times 1.429 \times 10^{-4} = 1.581$.

Step 3. The factor. $\dfrac{k_2}{k_1} = e^{1.581} = 4.86$.

Step 4. The time. $\dfrac{45\ \text{min}}{4.86} = 9.26\ \text{min}$.