Carnot Engine

Let ${\eta }_1$ <!-- [if gte mso 9]><xml> </xml><![endif]--> is the efficiency of an engine at T₁ = $447°C$ <!-- [if gte mso 9]><xml> </xml><![endif]--> and T₂ = $147°C$ <!-- [if gte mso 9]><xml> </xml><![endif]--> while ${\eta }_2$ <!-- [if gte mso 9]><xml> </xml><![endif]--> is the efficiency at T₁ = $947°C$ <!-- [if gte mso 9]><xml> </xml><![endif]--> and T₂ $47°C$ <!-- [if gte mso 9]><xml> </xml><![endif]-->. The ratio $\frac{{\eta }_1}{{\eta }_2}$ <!-- [if gte mso 9]><xml> </xml><![endif]--> will be