There are 3 military horses and 4 ordinary horses. Together 1 military horse and 1 ordinary horse can pull 40 dan of supplies. The team of horses can pull 137 dan of supplies. One dan is a unit of mass. How many supplies can 1 ordinary horse pull? how many supplies can 1 military horse pull?

For this problem write and solve a system of equations to answer the question. Then check the solution.