Hexane, $86\ \text{g/mol}$, and heptane, $100\ \text{g/mol}$, form an ideal solution. Take their vapour pressures at $298\ \text{K}$ as $20\ \text{kPa}$ and $6\ \text{kPa}$. A solution is made from $129\ \text{g}$ of hexane and $350\ \text{g}$ of heptane. What is the total vapour pressure above it?