Daniel and Evelyn are considering buying a house valued at $250,000. They have combined savings of $20,000, and the bank approved a $200,000 first mortgage. Another financial institution agreed to provide them with a $20,000 second mortgage. Also, Daniel has just won $10,000 from a lottery. If Daniel and Evelyn invested their money in guaranteed certificates, they would be able to earn 4%. The interest rates offered by the bank are 6% for the first mortgage and 7% for the second. Calculate their cost of capital. please show working

Daniel and Evelyn are considering buying a house valued at $250,000. They have combined savings of $20,000, and the bank approved a $200,000 first mortgage. Another financial institution agreed to provide them with a $20,000 second mortgage. Also, Daniel has just won $10,000 from a lottery. If Daniel and Evelyn invested their money in guaranteed certificates, they would be able to earn 4%. The interest rates offered by the bank are 6% for the first mortgage and 7% for the second. Calculate their cost of capital.